APA (7e ed.) Bronvermelding

Scheppach, R. C. (1972). State projections of the gross national product, 1970, 1980. Lexington Books.

Chicago (17e ed.) Bronvermelding

Scheppach, Raymond C. State Projections of the Gross National Product, 1970, 1980. Lexington, Mass: Lexington Books, 1972.

MLA (9e ed.) Bronvermelding

Scheppach, Raymond C. State Projections of the Gross National Product, 1970, 1980. Lexington Books, 1972.