APA

Liu R. H., McKeehan A. M., Edwards C., Foster G., Bensley W. D., Langner J. G. & Walia A. S. (19950203). Improved gas chromatography/mass spectrometry analysis of barbiturates in urine using centrifuge-based solid-phase extraction, methylation, with d5-pentobarbital as internal standard. : Journal of forensic sciences.

Chicago

Liu R H, McKeehan A M, Edwards C, Foster G, Bensley W D, Langner J G and Walia A S. 19950203. Improved gas chromatography/mass spectrometry analysis of barbiturates in urine using centrifuge-based solid-phase extraction, methylation, with d5-pentobarbital as internal standard. : Journal of forensic sciences.

Harvard

Liu R. H., McKeehan A. M., Edwards C., Foster G., Bensley W. D., Langner J. G. and Walia A. S. (19950203). Improved gas chromatography/mass spectrometry analysis of barbiturates in urine using centrifuge-based solid-phase extraction, methylation, with d5-pentobarbital as internal standard. : Journal of forensic sciences.

MLA

Liu R H, McKeehan A M, Edwards C, Foster G, Bensley W D, Langner J G and Walia A S. Improved gas chromatography/mass spectrometry analysis of barbiturates in urine using centrifuge-based solid-phase extraction, methylation, with d5-pentobarbital as internal standard. : Journal of forensic sciences. 19950203.