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
Holmes SJ, McKenna SP, Doward LC, Hunt SM, Shalet SM. Development of a questionnaire to assess the quality of life of adults with growth hormone deficiency. Endocrinology and metabolism. 1995 Jan 1;2(1):63-9.