Gaya APA

Allora, Ralph. (2009). Winning sales letters from prospect to close . United State of America: McGraw Hill.

Gaya Chicago

Allora, Ralph. Winning sales letters from prospect to close. United State of America: McGraw Hill, 2009. Buku.

Gaya MLA

Allora, Ralph. Winning sales letters from prospect to close. United State of America: McGraw Hill, 2009. Buku.

Gaya Turabian

Allora, Ralph. Winning sales letters from prospect to close. United State of America: McGraw Hill, 2009. Buku.