A. Ryan, “Causes of Cracks in the Plaster along Exterior Walls of Home,” 2009. http://ezinearticles.com/?Causes -of-Cracks-in-the-Plaster-Along-Exterior-Walls-of-the-Home&id=2259999
 United Nations, “Millennium Development Goals”. http: //www. undp.org/mdg/basics.shtml
 Ministry of Health and Welfare. www.parliament.go.tz/ bunge/parl_question
 Ngara District Council Authority, Works Department, 2008. www.ngaradc.com
 United States, Office of Archeology and Historic Preservation, Technical Preservation Services Division, “The Preservation of Historic Architecture-The US Government’s Official Guidelines for Preserving Historic Homes,” pp. 145-215.
 C. C. Roberts, “Evaluating cracks in Buildings,” C. Roberts Consulting Engineers Inc., Rochelle, http//www. croberts.com, p. 56.