@article {27964,
	title = {Ionic Exchange Separation of  Lanthanones from Egyptian Phosphate Ores and Their Analysis by Potentiometry Egypt. J. Chem. 24 (1) 7-14},
	year = {1981},
	author = {M.A. Zayed and A.M. El-Kammar and Amer, S. A}
}
