PUFFETT, R. (1990). Plumbing services volume 2, waste disposal, roof plumbing 2nd ed. McGraw Hill.
Chicago-viite (17. p.)PUFFETT, RJ. Plumbing Services Volume 2, Waste Disposal, Roof Plumbing 2nd Ed. McGraw Hill, 1990.
MLA-viite (8. p.)PUFFETT, RJ. Plumbing Services Volume 2, Waste Disposal, Roof Plumbing 2nd Ed. McGraw Hill, 1990.
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