Rockwood NJ, Jeon M. Estimating complex measurement and growth models using the R package PLmixed. Multivar Behav Res. 2019 Mar;54(2):288-306. doi: 10.1080/00273171.2018.1516541
Keenan A-M, McKenna SP, Doward LC, Conaghan PC, Emery P, Tennant A. OAQoL: development and preliminary validation of a needs-based quality of life measure for osteoarthritis. Poster presented at the American College of Rheumatology 2007 Annual Scientific Meeting; April 2007. Chicago, IL. [abstract] Rheumatology (Oxford). 2007; 46:162-3.
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.