M. El-Katcha, M. Soltan, K. El-Naggar, S. El-Shobokshy, and M. El-Erian, “LAYING PERFORMANCE, FAT DIGESTIBILITY AND LIVER CONDITION OF LAYING HENS SUPPLEMENTED WITH VITAMIN B12 OR BIOTIN AND/ OR BILE ACIDS IN DIET”, SVR, vol. 56, no. 22-Suppl, Mar. 2019.