APA

Covery(Stephen) ;Merrill(Roger), . (2000). First Thing First. : .

Chicago

Covery(Stephen) ;Merrill(Roger), . 2000. First Thing First. : .

Harvard

Covery(Stephen) ;Merrill(Roger), . (2000). First Thing First. : .

MLA

Covery(Stephen) ;Merrill(Roger), . First Thing First. : . 2000.