Callaghan, J. (1992). Costing for contracts. Directory of cocial change.
Cita Chicago Style (17a ed.)Callaghan, John. Costing for Contracts. London: Directory of cocial change, 1992.
Cita MLA (8a ed.)Callaghan, John. Costing for Contracts. Directory of cocial change, 1992.
Precaución: Estas citas no son 100% exactas.