UNEP Global Environmental Alert Service (GEAS) (2011) Athabasca Oil Sands, Require Massive Investments and Energy and Produce Massive Amounts of Oil and CO2. Alberta (Canada). United Nations Environment Program.
 UNEP Global Environmental Alert Service (GEAS) (2011) Oil Palm Plantation: Threats and Opportunities for Tropical Ecosystems. United Nations Environment Program. http://www.unep.org/pdf/Dec_11_Palm_Plantations.pdf
 US Department of Labor, Bureau of Labor Statistics (BLS) (2008) Quarterly Census of Employment and Wages. US Department of Labor, Bureau of Labor Statistics, Washington DC. http://data.bls.gov/labjava/outside.jsp?survey=en
 Morbidity and Mortality Weekly Report (MMWR) (2008) Fatalities Among Oil and Gas Extraction Workers—United States, 2003-2006. 25 April 2008, 57(16), 429-431. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5716a3.htm
 Mader, D. (1989) Hydraulic Proppant Fracturing and Gravel Packing. Elsevier.
 Wu, T. and Wu B. (2012) Corrosion Resistance of Ceramic Proppant in BaO-CaO-P2O5-Al2O3 System. Corrosion Science, 63, 399-403. http://dx.doi.org/10.1016/j.corsci.2012.06.025
 Fuss-Dezelic, T. (2014) Test Proppants to Mitigate Respirable Dust Hazards. World Oil, 235, 86-89.
 Rosenman, K.D., Reilly, M.J. and Henneberger, P.K. (2003) Estimating the Total Number of Newly Recognized Silicosis Cases in the United States. American Journal of Industrial Medicine, 44, 141-147.
 Wu, T., Wu, B. and Zhao, S. (2013) Acid Resistance of Silicon-Free Ceramic Proppant. Materials Letters, 92, 210-212.
 Rickards, A.R., Brannon, H.D. and Wood, W.D. (2006) High Strength Ultra-Light Weight Proppant Lends New Dimensions to Hydraulic Fracturing Applications. Production and Operations | Society of Petroleum Engineers, 21, 212- 221.
 Card, R.J., Howard, P.R. and Feraud, J.P. (1995) A Novel Technology to Control Proppant Back Production. Production and Operations | Society of Petroleum Engineers, 10, 271-276.
 Kulkarni, M.N. and Ochoa, O.O. (2012) Mechanism of Light Weight Proppant: A Discrete Approach. Composites Science and Technology, 72, 879-885. http://dx.doi.org/10.1016/j.compscitech.2012.02.017
 Kaufman, P.B., Anderson, R.W., Parker, M.A., Brannon, H.D., Neves, A.R., Abney, K.L., Joyce, S.A., Ziegler, M.J., Cortes, G.W.K.D.P. and Penny, G.S. (2007) Introducing New API/ISO Procedures for Proppant Testing. In: SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers. http://dx.doi.org/10.2118/110697-MS
 Ali, A., Road, J. and Pearce, W. (2009) Spirometry Pulmonary Function Testing in Clinical Practice. Springer-Verlag, London.
 American Thoracic Society (ATS) (1987) Standardization of Spirometry—1987 Update. American Review of Respiratory Disease, 136, 1285-1298. http://dx.doi.org/10.1164/ajrccm/136.5.1285
 Chen, J., Lou, J. and Liu, Z. (2003) Pulmonary Function in Fur-Processing Workers: A Dose-Response Relationship. Archives of Environmental Health, 58, 37-47. http://dx.doi.org/10.3200/AEOH.58.1.37-41
 Wang, F., Zou, Y., Shen, Y., Zhong, Y., Lv, Y., Huang, D., Chen, K., Li, Q., Qing, L., Xia, B. and Su, C. (2015) Synergistic Impaired Effect between Smoking and Manganese Dust Exposure on Pulmonary Ventilation Function in Guangxi Manganese-Exposed Workers Healthy Cohort (GXMEWHC). PLoS ONE, 10, e0116558.
 Mandal, A. and Majumder, R. (2013) Pulmonary Function of Paint Workers from West Bengal, India. Progress in Health Sciences, 3, 110-121.
 Mandal, A. and Majumder, R. (2013) Assessment of Pulmonary Function of Cement Industry Workers from West Bengal India. Progress in Health Sciences, 3, 65.
 Abejie, B.A., Wang, X., Kales, S.N. and Christiani, D.C. (2010) Patterns of Pulmonary Dysfunction in Asbestos Workers: A Cross-Sectional Study. Journal of Occupational Medicine and Toxicology, 5, 12.
 Chattopadhyay, B.P, Gangopadhyay, P.K, Bandopadhyay, T.S. and Alam, J. (2006) Comparison of Pulmonary Function Test Abnormalities between Stone Crushing Dust Exposed and Nonexposed Agricultural Workers. Environmental Health and Preventive Medicine, 11, 191-198. http://dx.doi.org/10.1007/BF02905278
 Hankinson, J.L., Odencrantz, J.R. and Fedan, K.B. (1999) Spirometric Reference Values from a Sample of the General US Population. American Journal of Respiratory and Critical Care Medicine, 159, 179-187.
 Schwartz, J., Katz, S.A., Fegley, R.W. and Tockman, M.S. (1988) Sex and Race Differences in the Development of Lung Function1-5. American Review of Respiratory Disease, 138, 1415-1421.
 Glindmeyer, H.W., Lefante, J.J., McColloster, C., Jones, R.N. and Weill, H. (1995) Blue-Collar Normative Spirometric Values for Caucasian and African-American Men and Women Aged 18 to 65. American Journal of Respiratory and Critical Care Medicine, 151, 412-422. http://dx.doi.org/10.1164/ajrccm.151.2.7842200
 Mannino, D.M., Gagnon, R.C., Petty, T.L. and Lydick, E. (2000) Obstructive Lung Disease and Low Lung Function in Adults in the United States: Data from the National Health and Nutrition Examination Survey, 1988-1994. Archives of Internal Medicine, 160, 1683-1689. http://dx.doi.org/10.1001/archinte.160.11.1683
 Peto, R., Speizer, F.E., Cochrane, A.L., Moore, F., Fletcher, C.M., Tinker, C.M., Higgins, I.T.T., Gray, R.G., Richards, S.M., Gilliland, J. and Norman-Smith, B. (1983) The Relevance in Adults of Air-flow Obstruction, but Not of Mucus Hypersecretion, to Mortality from Chronic Lung Disease: Results from 20 Years of Prospective Observation. American Review of Respiratory Disease, 128, 491-500. http://dx.doi.org/10.1164/arrd.1918.104.22.1681
 Burrows, B., Lebowitz, M.D., Camilli, A.E. and Knudson, R.J. (1986) Longitudinal Changes in Forced Expiratory Volume in One Second in Adults: Methodologic Considerations and Findings in Healthy Nonsmokers. American Review of Respiratory Disease, 133, 974-980.
 Asai, M., Tanaka, T., Kozu, R., Kitagawa, C., Tabusadani, M. and Senjyu, H. (2015) Effect of a Chronic Obstructive Pulmonary Disease (COPD) Intervention on COPD Awareness in a Regional City in Japan. Internal Medicine, 54, 163-169. http://dx.doi.org/10.2169/internalmedicine.54.2916
 Holguin, F., Folch, E., Redd, S.C. and Mannino, D.M. (2005) Comorbidity and Mortality in COPD-Related Hospitalizations in the United States, 1979 to 2001. Chest Journal, 128, 2005-2011.
 Hole, D.J., Watt, G.C.M., Davey-Smith, G., Hart, C.L., Gillis, C.R. and Hawthorne, V.M. (1996) Impaired Lung Function and Mortality Risk in Men and Women: Findings from the Renfrew and Paisley Prospective Population Study. British Medical Journal, 313, 711-715. http://dx.doi.org/10.1136/bmj.313.7059.711
 Wahba, W.M. (1983) Influence of Aging on Lung Function-Clinical Significance of Changes from Age Twenty. Anesthesia & Analgesia, 62, 764-776. http://dx.doi.org/10.1213/00000539-198308000-00011