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.
French M, Neighbors D, Carswell L, Williams R, Bush L. A model for estimating industry compliance costs of food labeling regulations. Agribusiness: An International Journal. 1993;8(2):165-86.