Hopper, L. J. (2010). Graphic standards field guide to hardscape. Wiley.
Chicago Style (17th ed.) CitationHopper, Leonard J. Graphic Standards Field Guide to Hardscape. Hoboken, N.J: Wiley, 2010.
MLA (9th ed.) CitationHopper, Leonard J. Graphic Standards Field Guide to Hardscape. Wiley, 2010.
Advarsel: Disse citationer er muligvist ikke 100% nøjagtige.