Hartman M, Bolton E, Fehnel SE. Accounting for age differences on the Wisconsin Card Sorting Test: decreased working memory, not inflexibility. Psychol Aging. 2001 Sep 1;16(3):385-99.
Lanza FL, Sontag SJ, Ciociola AA, Sykes DL, Heath AT, McSorley DJ. Ranitidine bismuth citrate plus clarithromycin: a dual therapy regimen for patients with duodenal ulcer. Helicobacter. 1998 Sep;3(3):212-21.
Graham DY, Breiter JR, Ciociola AA, Sykes DL, McSorley DJ. An alternative non-macrolide, non-imidazole treatment for curing helicobacter pylori and duodenal ulcers: ranitidine bismuth citrate plus amoxicillin. Helicobacter. 1998 Jun;3(2):125-31.