المؤلفون: Lahey, Carlotta Gonzales, King, Elizabeth W., Alleman, Irvin E., Baker, Betty Haynes

المصدر: National Geographic Magazine, 1951, Vol. XCIX, No. Two, P. 213.

المصدر: National Geographic Magazine, 1921, Vol. XXXIX, No. Four, P. 493.

Other Title: J. Stevens Arms Company

المصدر: National Geographic Magazine, 1910, Vol. XXI, No. Four, P. 373.

المصدر: National Geographic Magazine, 1919, Vol. XXXV, No. Two, P. 80.

Other Title: J. Stevens Arms Company

المصدر: National Geographic Magazine, 1924, Vol. XLV, No. Four, P. 499.