Cross-sectional study as a research method

The following resources are on Cross-sectional study as a Research Method:

1. Basic description: http://en.wikipedia.org/wiki/Cross-sectional_study
2. Brief description: http://www.ehib.org/faq.jsp?faq_key=41
3. On cross-sectional survey (pdf): http://www.iarc.fr/en/publications/pdfs-online/epi/cancerepi/CancerEpi-10.pdf