Chatchai Chansomboon, Mauricio A. Elzo, Thanathip Suwanasopee and Skorn Koonawootrittriron 2009. Genetic and Environmental Factors Affecting Weaning-to-First Service Interval in a Landrace-Large White Swine Population in Northern Thailand. Agriculture and Natural Resources. 43, 4 (Dec. 2009), 669–679.