Hackland , Brian (1984) The progressive party 1960-1980, political repsonses to structural change and class struggle. Collected Seminar Papers. Institute of Commonwealth Studies, 33 . pp. 121-138. ISSN 0076-0773

Hackland, Brian (1981) The economic and political context of the growth of the progressive federal party in South Africa, 1959-1978. Collected Seminar Papers. Institute of Commonwealth Studies, 27 . pp. 117-129. ISSN 0076-0773