SADC Course in Statistics Types and Sources of Errors in Statistical Data.
Online Survey Tools and their use in Public Health Vicky Ng, PhD Centre for Public Health and Zoonoses (CPHAZ), University of Guelph April 5, 2012.
Bmgt 311 chapter_11
Survey Methods and Errors
Syndicated sources of secondary data
(Source: Causeweb.org). Elementary Survey Sampling 7 th Edition By Scheaffer, Mendenhall, Ott and Gerow.
