I think I came across the article you were referring to; Physical Performance: Differences in Men and Women With and Without Low Back Pain, from American Academy of Physial Medicine and Rehabilitation, Vol 80, Feb. 1999.  Those 4 tasks are listed among 6 used to determine the difference in performace for persons with and without low back pain.  This article is nice, although the sample of subjects (21 men and 25 women for healthy, 33 men and 46 women with LBP) is too small to generalize.  The main reason this article is "nice" is that it substantiates the basic principle of our RMS tests (repetitions of a movement and time), but does not correlate well as to why we do RMS testing (repeat testing, and linking to RPDR).  Personally, I think using "norms" from this study for comparison to the performance of someone participating in an FCE is weak, at best. 

I would start by asking the author for the references. If he/she said they were compared to "normals" then they should be able to provide the references. And don't think it is being too forward to ask: you may actually be doing the author a favor by asking before a judge asks.