Open University. (1975). Operating systems: Prepared by the [Open University] Course Team ; in consultation with I.H. Witten. Computer languages and microprogramming / prepared by the Course Team. Open University Press.

Open University. Operating Systems: Prepared by the [Open University] Course Team ; in Consultation with I.H. Witten. Computer Languages and Microprogramming / Prepared by the Course Team. Milton Keynes: Open University Press, 1975.

Open University. Operating Systems: Prepared by the [Open University] Course Team ; in Consultation with I.H. Witten. Computer Languages and Microprogramming / Prepared by the Course Team. Open University Press, 1975.