1. THE ROLE OF INTEREST INCOME AND NONINTEREST INCOME ON THE PERFORMANCE OF FOUR LARGE SOUTH-AFRICAN BANKS. Authors: MERWE OBERHOLZER, GERT VAN DER WESTHUIZEN.2. THE ROLE OF INTEREST INCOME AND NON-INTEREST INCOME ON THE RELATIVE EFFICIENCY OF BANK REGIONS: THE CASE OF A LARGE SOUTH AFRICAN BANK. Authors: GERT VAN DER WESTHUIZEN.3. THE RELATIVE EFFICIENCY OF BANKS IN LENDING AND BORROWING: EVIDENCE FROM DATA ENVELOPMENT ANALYS. Authors: GERT VAN DER WESTHUIZEN.