“Various Measures of Tree Vigor, Yield, and Yield Efficiency of Apple Trees in the 1990 NC-140 Systems Trial As Influenced by Location, Cultivar, and Orchard System”. Journal of the American Pomological Society 56, no. 4 (October 1, 2002): 208–214. Accessed February 10, 2026. https://journal.americanpomological.org/index.php/jofaps/article/view/2489.