J. P. Mathias, J. A. Zerkowski, C. T. Seto, E.E. Simanek, and G. M. Whitesides. 1994. “Structural Preferences of Hydrogen-Bonded Networks in Organic Solution–the Cyclic CA₃•M₃ 'Rosette'.” J. Am. Chem. Soc., 116, Pp. 4316-4325.