tribes, noteworthy persons and important place names are arranged together. Cross-references are used to lead the reader from names that are familiar to alternate names that may not be. Internal cross-references also appear frequently within entries, where they are identified by the Arabic letter mīm to denote 'see' or 'see also'. References Genealogy publications Encyclopedias of culture and ethnicity Non-fiction books about Sudan African encyclopedias 20th-century encyclopedias