TY - JOUR T1 - Causation, bias and confounding: a hitchhiker's guide to the epidemiological galaxy JF - Journal of Family Planning and Reproductive Health Care JO - J Fam Plann Reprod Health Care SP - 185 LP - 190 DO - 10.1783/147118908784734873 VL - 34 IS - 3 AU - Samuel Shapiro Y1 - 2008/07/01 UR - http://jfprhc.bmj.com/content/34/3/185.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -