1. Macdonald J.A. recognition of “obligation—imperfect because it cannot be enforced”: 1968 (2) S.A. 284, 378D–E.
2. Williams G. L. , “The Defence of Necessity” (1953) 6 C.L.P. 216
3. Minister of the Interior v. Harris, 1952 (4) S.A. 769
4. Stratford A.C.J. in Ndlwana v. Hofmeyr [1937] A.D. 229, 237.