Citação norma APA

Iowa. State Planning Board. Soil Conservation Committee. (1938). Soil conservation districts for Iowa? Iowa State Planning Board.

Citação norma Chicago

Iowa. State Planning Board. Soil Conservation Committee. Soil Conservation Districts for Iowa? [Des Moines]: Iowa State Planning Board, 1938.

Citação norma MLA

Iowa. State Planning Board. Soil Conservation Committee. Soil Conservation Districts for Iowa? Iowa State Planning Board, 1938.

Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.