1. A.K. Ismail et al. “Improvement of Rheological Properties of Egyptian Bentonitic Clay through Alkali Activation,” IXth Int. Clay Conf. (Strasbourg, France: Institut Geologie, 1989), pp. 149–252.
2. N.S. Felix, “Physico-chemical Studies on Bentonites with Special References to Fayoum Deposits” (Ph.D. thesis, Faculty of Science, Cairo University, 1977).
3. A.I. Ibrahim, “Processing of Egyptian Bentonites for Industrial Applications” (Ph.D. thesis, Faculty of Science, Cairo University, 1988).
4. M.M. Ashry, Geochimica et Cosmochimica Acta, 37 (1973), pp. 2449–2258.
5. R. Ohrodorf, Geochim Cosmochim. Acta, 32 (1968), pp. 191–208.