Manning, M., Przybylski, J. P., Olma, A., Klis, W. A., Kruszynski, M., Wo, N. C., Pelton, G. H., & Sawyer, W. H. (1987). No requirements of cyclic conformation of antagonists in binding to vasopressin receptors. Nature, 329(6142), 839-40. doi:10.1038/329839a0