Copley-Merriman C, Yang X, Juniper M, Amin S, Yoo HK, Sen SS. Natural history and disease burden of neurofibromatosis type 1 with plexiform neurofibromas: a systematic review. Adolesc Health Med Ther. 2021 May 19;12:55-66. doi: 10.2147/AHMT.S303456
Roberts J, Price J, Nelson LM, Burchinal M, Hennon E, Barnes B. Receptive vocabulary, expressive vocabulary, and speech production of boys with fragile X syndrome in comparison to boys with Down syndrome. Am J Ment Retard. 2007 May 1;112:177-93.