• 'n Studie van dorperskaapboerdery in die dorperlandgebied 

      Ackermann, Jacobus Johannes (Stellenbosch : Stellenbosch University, 1993-12)
      ENGLISH ABSTRACT: A model of interdependents that makes provision for the particular needs of dorper sheep farming and is based on the relationship between the main groups of behaviour determined variables, was constructed. ...