APA
Naterop B. J. . W. E. &. H. E., . (1987). Business letters for all. OUP, Oxford: .
Chicago
Naterop Bertha J Weis Erich & Haberfellner Eva, . 1987. Business letters for all. OUP, Oxford: .
Harvard
Naterop B. J. . W. E. &. H. E., . (1987). Business letters for all. OUP, Oxford: .
MLA
Naterop Bertha J Weis Erich & Haberfellner Eva, . Business letters for all. OUP, Oxford: . 1987.