Gaya APA

Spengler, Joseph J. (1975). Population and Amercia's future . San francisco: W.H Freeman and company.

Gaya Chicago

Spengler, Joseph J. Population and Amercia's future. San francisco: W.H Freeman and company, 1975. Text.

Gaya MLA

Spengler, Joseph J. Population and Amercia's future. San francisco: W.H Freeman and company, 1975. Text.

Gaya Turabian

Spengler, Joseph J. Population and Amercia's future. San francisco: W.H Freeman and company, 1975. Print.