Urban, E.K., Fry, C.H. and Keith S. (1986). The birds of Africa. Volume II. Guineafowl to Pigeons. ISBN 0-12-137302-9; pp xvi + 552; 32 colour plates. London: Academic Press.[939]
Uljanov, N.I.(1998). Nowyj Gamlet (New Hamlet). Znanije-Sila(Moscow). pps 151-152.(Soqotra as Prospero's Island of Shakespeare). In Russian [1160]
Uvarov, B.P. and Popov, G.B. (1957). The Saltatorial Orthoptera of Socotra. 38 figures; 2 habitat photographs (Plate 8); 1 map. Journal of the Linnean Society (Zoology), London 43(4;292): 359-389.[941]
Uvarov, B.P. (1952). Studies in the Arabian Orthoptera. III. New genera, species and subspecies collected by the Anti Locust Missions. Journal of the Linnean Society (Zoology), London 42(284): 176-194.[940]