As I said, the authorative work was done earlier:
Steen J, et al. [See Related Articles]
Basal serum gastrin concentration related to complications, blood groups, and season in duodenal ulcer.
Scand J Gastroenterol. 1982 Jun; 17(4): 529-532. No abstract available.
PMID: 7134880; UI: 83040976.
Jori GP, et al. [See Related Articles]
Influence of blood group and secretor status on gastric acidity.
Am J Dig Dis. 1969 Jun; 14(6): 380-384. No abstract available.
PMID: 5787590; UI: 69212387.
Habbick BF, et al. [See Related Articles]
Duodenal ulcer in childhood. A study of predisposing factors.
Arch Dis Child. 1968 Feb; 43(227): 23-27. No abstract available.
PMID: 5642980; UI: 68190152.
Vesely KT, et al. [See Related Articles]
Clinical data and characteristics differentiating types of peptic ulcer.
Gut. 1968 Feb; 9(1): 57-68. No abstract available.
PMID: 5640928; UI: 68161571.
Vesely KT. [See Related Articles]
[Review of factors which can be significant in the origin of peptic ulcer].
Vnitr Lek. 1967 Dec; 13(12): 1163-1170. Czech. No abstract available.
PMID: 6078820; UI: 68104264.
Denborough MA. [See Related Articles]
ABO blood group, secretor status and gastric secretion.
Australas Ann Med. 1966 Nov; 15(4): 314-317. No abstract available.
PMID: 5339638; UI: 67183062.
Maur M, et al. [See Related Articles]
[Secretor state of the group-ABH specific substance and gastroduodenal pathology].
Prensa Med Argent. 1966 Jun 10; 53(23): 1288-1292. Spanish. No abstract available.
PMID: 5975438; UI: 67217619.