APA

Carolyn Keene, .The clue of the whistling Bugpipes ( Nancy Drew-41). : .

Chicago

Carolyn Keene, .The clue of the whistling Bugpipes ( Nancy Drew-41). : .

Harvard

Carolyn Keene, .The clue of the whistling Bugpipes ( Nancy Drew-41). : .

MLA

Carolyn Keene, .: . .