Pumrojana, P. et al. 2015. Influence of Fatty Acid Composition of Soybean Oil Vs. Beef Tallow on Egg Yolk Fatty Acid Profiles of Laying Hens. Pakistan Journal of Nutrition. 14, 7 (Jun. 2015), 383–387. DOI:https://doi.org/10.3923/pjn.2015.383.387.