El-Toubi, M.R. & Hamdy, A.R. (1959)
Studies on the head skeleton of Rhinobatus halavi, Rhynchobatus djiddensis and Trygon kuhlii. Publications of the Marine Biological Station of Al–Ghardaqa, 10, 3–40
El-Toubi, M.R. (1952)
The development of the chondrocranium of the spiny dogfish, Acanthias vulgaris (Squalus acanthias). Part II: Branchial arches and extravisceral cartilages. Journal of Morphology, 90(1), 33–64
DOI: 10.1002/jmor.1050900103
El-Toubi, M.R. (1949)
The development of the chondrocranium of the spiny dogfish, Acanthias vulgaris (Squalus acanthias). Part I. Neurocranium, mandibular and hyoid arches. Journal of Morphology, 84(2), 227–279
DOI: 10.1002/jmor.1050840204
El-Toubi, M.R. (1947)
The development of the spiracular cartilages of the spiny dogfish, Acanthias vulgaris (Squalus acanthias). Biological Bulletin, 93(2), 287–295