1. 49 CFR part 40.29(n)(6)
2. Department of Health and Human Services [DHHS] Mandatory Guidelines for Federal workplace drug testing programs. Federal Register 53 [April 11]: 11970-11989, 1988
3. Drug testing ramifications: A response
4. Nuclear Regulatory Commission: Fitness for Duty Programs. Federal Register 54 [June 7]:24, 468-524, 508, 1989
5. Omnibus Transportation Employee Testing Act of 1991. Pub Law 102-143, 102 Congress, October 28, 1991