O. Bondoc and J. Isubol, “Reasons for Culling in Relation to Longevity and Lifetime Efficiency of Landrace and Large White Sows in a Nucleus Breeding Farm in the Philippines”, Trop. Anim. Sci. J., vol. 45, no. 1, pp. 30–36, Feb. 2022, doi: 10.5398/tasj.2022.45.1.30.