APA aipamena

Sapsford,David, & Ladd,James. (1978). Essential economics. Hart-Davis Educational.

Chicago Style aipamena

Sapsford,David, and Ladd,James. Essential Economics. Great Britain: Hart-Davis Educational, 1978.

MLA aipamena

Sapsford,David, and Ladd,James. Essential Economics. Hart-Davis Educational, 1978.