Bull, W. J. (1991). Precast Concrete Raft Units. Blackie.
Chicago Edition CitationBull, W. John. Precast Concrete Raft Units. Glasgow: Blackie, 1991.
Cita MLABull, W. John. Precast Concrete Raft Units. Blackie, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.