Ling, Geoffrey; et al. (1981). "Methadone: radioimmunoassay and pharmacokinetics in the rat". Journal of Pharmacology and Experimental Therapeutics. 217 (1): 147–151. PMID7205649.
Scudellari, Megan (September 1, 2012). "Missing Touch". The Scientist. Retrieved June 7, 2013.
usuhs.mil
"COL Geoffrey Ling". Uniformed Services University of the Health Sciences. July 25, 2012. Archived from the original on June 9, 2013. Retrieved June 7, 2013.
"COL Geoffrey Ling". Uniformed Services University of the Health Sciences. July 25, 2012. Archived from the original on June 9, 2013. Retrieved June 7, 2013.