Hargis, P.J. Jr.; Preppernau, B.L. & Osbourn, G.C. Automated detection and reporting of Volatile Organic Compounds (VOCs) in complex environments, report, March 1, 1997; (https://digital.library.unt.edu/ark:/67531/metadc675442/m1/1/: accessed April 25, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .