National Federation of Roofing Contractors. (1980). Roofing Contractor: Journal of the National Federation of Roofing Contractors / National Federation of Roofing Contractors. Clifford Frost Limited.
Chicago-Zitierstil (17. Ausg.)National Federation of Roofing Contractors. Roofing Contractor: Journal of the National Federation of Roofing Contractors / National Federation of Roofing Contractors. Wimbledon: Clifford Frost Limited, 1980.
MLA-Zitierstil (9. Ausg.)National Federation of Roofing Contractors. Roofing Contractor: Journal of the National Federation of Roofing Contractors / National Federation of Roofing Contractors. Clifford Frost Limited, 1980.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.