APA

Nelson H. D., . (1980). Chad. Washington: The American University Forrign Areas Study.

Chicago

Nelson Harold D, . 1980. Chad. Washington: The American University Forrign Areas Study.

Harvard

Nelson H. D., . (1980). Chad. Washington: The American University Forrign Areas Study.

MLA

Nelson Harold D, . Chad. Washington: The American University Forrign Areas Study. 1980.