Wallace, J.H. (1967)
The batoid fishes of the east coast of Southern Africa. Part II: Manta, Eagle, Duckbill, Cownose, Butterfly and Sting Rays. Investigational Report Oceanographic Research Institute, 16, 1–56

Du Preez, H.H. & Mclachlan, A. & Marais, J.F.K. (1988)
Oxygen consumption of two nearshore marine elasmobranchs, Rhinobatos annulatus (Müller & Henle, 1841) and Myliobatus aquila (Linnaeus, 1758). Comparative Biochemistry and Physiology – Part A, Physiology, 89(2), 283–294
DOI: 10.1016/0300-9629(88)91094-8

Du Preez, H.H. & Mclachlan, A. & Marais, J.F.K. & Cockcroft, A.C. (1990)
Bioenergetics of fishes in a high-energy surf-zone. Marine Biology, 106(1), 40513
DOI: 10.1007/BF02114669