Raghunathan K, Layton JB, Ohnuma T, Shaw AD. Observational research using propensity scores. Adv Chronic Kidney Dis. 2016 Nov;23(6):367-72. doi: 10.1053/j.ackd.2016.11.010
Scott Graham R, Samsell BJ, Proffer A, Moore MA, Vega RA, Stary JM, Mathern B. Evaluation of glycerol-preserved bone allografts in cervical spine fusion: a prospective, randomized controlled trial. J Neurosurg Spine. 2015 Jan;22(1):1-10. doi: 10.3171/2014.9.SPINE131005
Wong WM, Hawe E, Li LK, Miller GJ, Nicaud V, Pennacchio LA, Humphries SE, Talmud PJ. Apolipoprotein AIV gene variant S347 is associated with increased risk of coronary heart disease and lower plasma apolipoprotein AIV levels. Circ Res. 2003;92(9):969-75.