(1971). Specification for concrete roofing tiles and fittings. London: British Standards Institution.
Παραπομπή Chicago StyleSpecification for Concrete Roofing Tiles and Fittings. London: British Standards Institution, 1971.
Παραπομπή MLASpecification for Concrete Roofing Tiles and Fittings. London: British Standards Institution, 1971.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.