Hi Emily,
Two challenging topics!
For ADA, if you’re purely looking for the laws, I would just go straight to the source: https://www.ada.gov/.
There is an article (kind of old from 1996) that gives some good background info about ADA and how it impacts peds PT. The stats will be old but the general info is still good.
Lowes L, Effgen S. The Americans with Disabilities Act of 1990: Implications for Pediatric Physical Therapists. Pediatric Physical Therapy 1996;8(3):111-116.
For estim, I found a few articles that were helpful:
Bosques G, Martin R, McGee L, Sadowsky C. Does therapeutic electrical stimulation improve function in children with disabilities? A comprehensive literature review. J Pediatr Rehabil Med. 2016;9(2):83-99. doi:10.3233/PRM-160375
Singleton C, Jones H, Maycock L. Functional electrical stimulation (FES) for children and young people with cerebral palsy. Paediatrics and Child Health. 2019;29(11):498-502.
https://www.sciencedirect.com/science/article/pii/S1751722219301763
Chiu HC, Ada L. Effect of functional electrical stimulation on activity in children with cerebral palsy: a systematic review. Pediatr Phys Ther. 2014;26(3):283-288. doi:10.1097/PEP.0000000000000045
I hope this helps!
Jessica