CIP priority
In the CIP rules the conventional order of ligands established for the purpose of unambiguous designation of stereoisomers. It is deduced by application of sequence rules, the authoritative statement of which appears in R.S. Cahn, C.K. Ingold and V. Prelog, Angew. Chem.78, 413-447 (1966), Angew. Chem. Internat. Ed. Eng.5, 385-415, 511 (1966); and V. Prelog and G. Helmchen, Angew. Chem. 94, 614-631 (1982), Angew.Chem. Internat. Ed. Eng. 21, 567-583 (1982).
PAC, 1996, 68, 2193 (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2203