ASHWORTH, A. H. (2013). Willis's practice and procedure for the quantity surveyor. John Wiley & Sons.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रASHWORTH, Allan Hogg. Willis's Practice and Procedure for the Quantity Surveyor. John Wiley & Sons, 2013.
एमएलए (9वां संस्करण) प्रशस्ति पत्रASHWORTH, Allan Hogg. Willis's Practice and Procedure for the Quantity Surveyor. John Wiley & Sons, 2013.
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