Cowan, Lester, « Camera and Projection Apertures », Journal of the Society of Motion Picture Engineers, vol. XIV, no 1, , p. 108–121 (OCLC1951231, lire en ligne)
« Society Announcements, New Dimensional Standards », Journal of the Society of Motion Picture Engineers, vol. XIX, no 1, , p. 924 (OCLC1951231, lire en ligne)
Cowan, Lester, « Camera and Projection Apertures », Journal of the Society of Motion Picture Engineers, vol. XIV, no 1, , p. 108–121 (OCLC1951231, lire en ligne)
« Society Announcements, New Dimensional Standards », Journal of the Society of Motion Picture Engineers, vol. XIX, no 1, , p. 924 (OCLC1951231, lire en ligne)