Collier's encyclopedia, with bibliography and index; Volume 2
P.F. Collier & Son, 1954
 Buku Referensi
Collier's encyclopedia, with bibliography and index; Volume 5
P.F. Collier & Son, 1954
 Buku Referensi
Collier's encyclopedia, with bibliography and index; Volume 9
P.F. Collier & Son, 1954
 Buku Referensi
Collier's encyclopedia, with bibliography and index; Volume 13
P.F. Collier & Son, 1954
 Buku Referensi
Collier's encyclopedia, with bibliography and index; Volume 16
P.F. Collier & Son, 1954
 Buku Referensi