Seeley, Ellen W.; Grinspoon, Steven - Harvard Medical School (25 November 2016). "Chapter 2: Patient-Oriented Research". In David Robertson; Gordon H. Williams (eds.). Clinical and Translational Science: Principles of Human Research. Academic Press. p. 13, parag. 3 under "Clinical Trials". ISBN978-0-12-802111-8. Retrieved 2018-07-30.
Stephen M. Stigler (November 1992). "A Historical View of Statistical Concepts in Psychology and Educational Research". American Journal of Education. 101 (1): 60–70. doi:10.1086/444032. S2CID143685203.
Stephen M. Stigler (November 1992). "A Historical View of Statistical Concepts in Psychology and Educational Research". American Journal of Education. 101 (1): 60–70. doi:10.1086/444032. S2CID143685203.