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
Yopp JM, Park EM, Edwards T, Deal A, Rosenstein DL. Overlooked and underserved: widowed fathers with dependent-age children. Palliat Support Care. 2015 Oct;13(5):1325-34. doi: 10.1017/S1478951514001321
Johannes CB, Caro JJ, Hartz SC, Marrs R. Adverse effects of ovulatory stimulants: a review. Assist Reprod Rev. 1993;3:68-74.