Pals G, Azuma T, Mohandas TK, Bell GI, Bacon J, Samloff IM, Walz DA, Barr PJ, Taggart RT (February 1989). "Human pepsinogen C (progastricsin) polymorphism: evidence for a single locus located at 6p21.1-pter". Genomics. 4 (2): 137–48. doi:10.1016/0888-7543(89)90292-9. PMID2567697.
Pals G, Azuma T, Mohandas TK, Bell GI, Bacon J, Samloff IM, Walz DA, Barr PJ, Taggart RT (February 1989). "Human pepsinogen C (progastricsin) polymorphism: evidence for a single locus located at 6p21.1-pter". Genomics. 4 (2): 137–48. doi:10.1016/0888-7543(89)90292-9. PMID2567697.