APA

Road Research Laboratory. Overseas bulletin nr 12 [TRRL], . (1960). Roadmaking gravels and soils in Central Africa. Harmondsworth: Road Research Laboratory. Overseas bulletin nr 12 [TRRL].

Chicago

Road Research Laboratory. Overseas bulletin nr 12 [TRRL], . 1960. Roadmaking gravels and soils in Central Africa. Harmondsworth: Road Research Laboratory. Overseas bulletin nr 12 [TRRL].

Harvard

Road Research Laboratory. Overseas bulletin nr 12 [TRRL], . (1960). Roadmaking gravels and soils in Central Africa. Harmondsworth: Road Research Laboratory. Overseas bulletin nr 12 [TRRL].

MLA

Road Research Laboratory. Overseas bulletin nr 12 [TRRL], . Roadmaking gravels and soils in Central Africa. Harmondsworth: Road Research Laboratory. Overseas bulletin nr 12 [TRRL]. 1960.