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
Hauber B, Candrilli S, Snyder EH, McBurney CR. Validation of a model to assess long-term disease progression in Alzheimer's disease patients treated with rivastigmine. Neurobiol Aging. 2004 Jan 1;25:S136.
Mines D, Abbuhl SB. Hydroxyapatite pseudopodagra in a young man: acute calcific periarthritis of the first metatarsophalangeal joint. Am J Emerg Med. 1996 Mar;14(2):180-2.