S. M. Nusser, L. L. Miller, K. Clarke and M. F. Goodchild, “Future Views of Field Data Collection in Statistical Surveys,” Proceedings of Digital Government Dot Org 2001 National Conference on Digital Government Research, Los Angeles,
 University of Washington, “Cell Phones Become Handheld Tools for Global Development”, 2009.
 ITU (2010) Measuring the Information Society, ICT Development Index. Geneva: ITU.
 K. Moe, B. Dwolatzky and R. Olst, “Designing a Usable Mobile Application for Field Data Collection,” IEEE AFRICON, 2004, pp. 1187-1192.
 S. Mour?o and K. Okadata, “Mobile Phone as a Tool for Data Collection in Field Research,” World Academy of Science, Engineering and Technology, 2010, November 22, 2010.
 K. K. Lwin and Y. Murayama, “Modelling of Urban Green Space Walkability: Eco-friendly Walk Score Calculator,” Computers, Environment and Urban Systems,.
 S. M. Nusser, L. L. Miller, K. Clarke and M. F. Goodchild, “Geospatial IT for Mobile Field DataCollection,” Communications of the ACM, Vol. 46, No. 1, 2003, pp. 64-65. doi:10.1145/602421.602446
 K. K. Lwin and Y. Murayama, “Personal Field Data Collection by UM-FieldGIS (UMPC, UltraMobile PC and Embedded Google Map API),” Proceedings of the 16th Annual Meeting of GIS Association of Japan, Hokkaido University, 20-21October 2007.
 Y. Murayama, “Systematization of Fieldwork Methodology: A Study on Capture, Management, Analysis and Circulation of Geographical Data,” Grant-in-Aid for Scientific Research A, JSPS, 2010.
 Y. Murayama and K. K. Lwin, “Population Estimation of Rapidly Growing Cities in Southeast Asia Using GIS/RS”, Grant-in-Aid for Scientific Research, JSPS, 2010.