Halophytes as a resource for livestock and for rehabilitation of degraded lands : proceedings of the International Workshop on Halophytes for Reclamation of Saline Wastelands and as a Resource for Livestock, Problems and Prospects, Nairobi, Kenya, 22-27 November 1992 / ed. by Victor R. Squires and Ali T. Ayoub / Dordrecht : Kluwer Academic , cop. 1994