OSTWALD, P. F. (1984). Cost Estimating Philip F. Ostwald. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)OSTWALD, Philip F. Cost Estimating Philip F. Ostwald. Prentice-Hall, 1984.
Lua MLA (8ú heag.)OSTWALD, Philip F. Cost Estimating Philip F. Ostwald. Prentice-Hall, 1984.
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