00771nam0-22002891i-450-99000369082040332119930714000000.006-7484-372-X000369082FED01000369082(Aleph)000369082FED01000369082Aug-15,-D----1992km-0yita-0103----baENGUSStructural holesthe social structure of competitionRonald S. BurtCambridgeMass.VIII, 313 p.25 cmUSCambridgeBurt,Ronald S.118943ITUNINARICAUNIMARCBK9900036908204033211-6-373-TI7159ECAECAStructural holes261655UNINA