Goto, J; Hasegawa, K; Nambara, T; Iida, T. Studies on steroids. CCLIV. Gas chromatographic-mass spectrometric determination of 4- and 6-hydroxylated bile acids in human urine with negative ion chemical ionization detection. Journal of Chromatography. 1992, 574 (1): 1–7. PMID 1629271. doi:10.1016/0378-4347(92)80091-4.
Goto, J; Hasegawa, K; Nambara, T; Iida, T. Studies on steroids. CCLIV. Gas chromatographic-mass spectrometric determination of 4- and 6-hydroxylated bile acids in human urine with negative ion chemical ionization detection. Journal of Chromatography. 1992, 574 (1): 1–7. PMID 1629271. doi:10.1016/0378-4347(92)80091-4.