APA

Covey S. R., Merrill A. R. & Merrill R. R. (1994). First things first. New York, New York: Simon & Schuster.

Chicago

Covey Stephen R, Merrill A Roger and Merrill Rebecca R. 1994. First things first. New York, New York: Simon & Schuster.

Harvard

Covey S. R., Merrill A. R. and Merrill R. R. (1994). First things first. New York, New York: Simon & Schuster.

MLA

Covey Stephen R, Merrill A Roger and Merrill Rebecca R. First things first. New York, New York: Simon & Schuster. 1994.