APA
Nelson H. D., . (1973). Area handbook for the Democratic Republic of Sudan. Washington: U.S. Govt. Print. Off.
Chicago
Nelson Harold D, . 1973. Area handbook for the Democratic Republic of Sudan. Washington: U.S. Govt. Print. Off.
Harvard
Nelson H. D., . (1973). Area handbook for the Democratic Republic of Sudan. Washington: U.S. Govt. Print. Off.
MLA
Nelson Harold D, . Area handbook for the Democratic Republic of Sudan. Washington: U.S. Govt. Print. Off. 1973.