Developments in arid zone ecology and environmental quality : proceedings of an international meeting ; 12th Scientific Conference of the Israel Ecological Society at the Hebrew University of Jerusalem, Israel, May 12 - 13, 1981 - Shuval, Hillel I. (Hrsg.); Agudah ha-Yiśreʼelit le-eḳologyah (Proceedings of an international meeting [of the Israel Ecological Society, 1981)