Bhuiyan A R, Lauridsen C, Howlider A R and Jakobsen K 2004: Importance of vitamin A supplementation for performance of Sonali chickens under smallholder farm conditions in a tropical climate. Livestock Research for Rural Development. Vol. 16, Art. #83. Retrieved ,
from http://www.lrrd.org/lrrd16/10/bhui16083.htm