Goldstein, L. & Oppelt, W.W. & Maren, T.H. (1968)
Osmotic regulation and urea metabolism in the lemon shark Negaprion brevirostris. American Journal of Physiology, 215(6), 1493–1497

Oppelt, W.W. (1967)
The control of ventricular-fluid production in the shark. In P.W. Gilbert, R.F. Mathewson, & D.P. Rall, (Eds.), Sharks, skates and rays. (pp. 381–388). John Hopkins Press, Baltimore

Bering, E.A. & Rall, D.P. & Oppelt, W.W. (1967)
Hydrodynamics of the cerabral ventricular fluid in the shark. In P.W. Gilbert, R.F. Mathewson, & D.P. Rall, (Eds.), Sharks, skates and rays. (pp. 389–398). John Hopkins Press, Baltimore

Oppelt, W.W. & Adamson, R.H. & Zubrod, C.G. & Rall, D.P. (1966)
Further observations on the physiology and pharmacology of elasmobranch ventricular fluid? Comparative Biochemistry and Physiology, 17(3), 857–866
DOI: 10.1016/0010-406X(66)90126-5

Oppelt, W.W. & Patlak, C.S. & Zubrod, C.G. & Rall, D.P. (1964)
Ventricular fluid production rates and turnover in elasmobranchii. Comparative Biochemistry and Physiology, 12(2), 171–177
DOI: 10.1016/0010-406X(64)90171-9

Oppelt, W.W. & Bunim, L. & Rall, D.P. (1963)
Distribution of glucose in the spiny dogfish (S. Acanthias) and the brier skate (R. Eglanteria). Life Sciences, 2(7), 497–503
DOI: 10.1016/0024-3205(63)90139-5