R. A. Dixon, I. S. Sigal, M. R. Candelore, R. B. Register, W. Scattergood, E. Rands, C. D. Strader,
Structural features required for ligand binding to the beta-adrenergic receptor. The EMBO Journal. ,vol. 6, pp. 3269- 3275 ,(1987) ,
10.1002/J.1460-2075.1987.TB02645.X