Özden, I., İpekoğlu, M., Mahmutyazıcıoğlu, N., Altıntaş, S., “Effect of Al2O3, ZrO2, and TiO2 Addition on the Mechanical Properties and the Microstructure of Natural Hydroxyapatite Obtained from Calf Femoral Bone, Key Engineering Materials, 493-494, 199-204, 2011.