APA

(1999). Vision - Vol.92 No.2 (1999). México: Vision Incorporated.

Chicago

1999. Vision - Vol.92 No.2 (1999). México: Vision Incorporated.

Harvard

(1999). Vision - Vol.92 No.2 (1999). México: Vision Incorporated.

MLA

Vision - Vol.92 No.2 (1999). México: Vision Incorporated. 1999.