Njue AI, Prichard RK. Efficacy of ivermectin in calves against a resistant Cooperia oncophora field isolate. Parasitol Res. 2004 Aug 1;93(5):419-22.
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.