Vajda, S. (1969). Planning by mathematics. Sir Isaac Pitman and Sons Ltd.
Cita Chicago (17th ed.)Vajda, S. Planning by Mathematics. London: Sir Isaac Pitman and Sons Ltd, 1969.
Cita MLA (9th ed.)Vajda, S. Planning by Mathematics. Sir Isaac Pitman and Sons Ltd, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.