Groenwold R, Uddin M, Roes K, de Boer A, Rivero-Ferrer E, Martin E, Gatto N, Klungel O. Instrumental variable analysis in randomized trials with non-compliance and observational pharmacoepidemiologic studies. OA Epidemiology. 2014 May 9;2(1):9.
Watts (Wideman) K, McAvinchey G, Quiroz R. Language services in survey research. ATA Chronicle. 2002 Jul;31(7):36-7.