1. Omnibus Transportation Employee Testing Act of 1991: Public Law 102-143, Title V, [H.R. 2942];102d Congress, 105 STAT,1991
2. Executive Order 12564—Drug-free federal workplace, 51 FR 32889, 3 CFR, 1986 Comp,1986
3. 49 CFR Part 40 [Docket OST–2010–0026], RIN 2105–AD95, Procedures for transportation workplace drug and alcohol testing programs;Department of Transportation;Federal Register/Rules and Regulations,2010
4. (2012) Electronic Code of Federal Regulations (e-CFR), Title 49: Transportation, Part 40—Procedures for transportation workplace drug and alcohol testing programs, Subpart F—Drug testing laboratories
5. The medical review officer handbook, 9th edition, Chapter 4: MRO practices and procedures, 4.4: The MRO's role in managing specimen validity and integrity, 4.4.2: MRO verification of adulterated, substituted and dilute specimens;Shults,2009