Twin low-oblique photography and the Twinplex plotter - Geological Survey (U.S.) (Washington, 1952)
"The text of this circular is an adaptation and combination of the following papers: 1. Hopkins, B. T., 1951, The Twinplex plotter for low-oblique photography. [Unpublished] 2. Radlinski, W. A., 1952, Convergent low-oblique photography and its application to the Twinplex: Photogrammetric engineering, v. 18, no. 3, pp. 596-597. 3. Thompson, M. M., 1950, the Twinplex, a new stereoplotting instrument; U. S. Geological Survey Circ. 82."
Keywords: Photographic surveying; Surveying -- Instruments