Reinsch, Paul S.
Commercial Press, 1921
Buku Teks
Roelofs, H. Mark
The Dorsey press, 1968
Buku Teks
by Carlton Clymer Rodee ... [et al.]
McGraw-Hill Kogakusha, 1976
Buku Teks
Roucek, Joseph S., author
Thomas Y. Crowell Company, 1950
Buku Teks
Hague, Rod., author
Palgrave Macmillan , 2013
Buku Teks