Twin low-oblique photography and the Twinplex plotter, 
prepared by the Topographic Division, Research and Technical Control Branch, Section of Photogrammetry. 
 - Washington,  1952. 
 - iii, 18 p.  illus., diagrs.  27 cm. 
 - Geological Survey circular  222 .
<br/><br/> "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 [Unpublished] 2.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." 
<br/><br/><label>LCCN: </label>gs 53000080  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Photographic surveying.<br/>Surveying--Instruments.
<br/><br/><label>LC Class. No.: </label>QE75  / .C5 no. 222 
<br/><br/><label>Dewey Class. No.: </label>526.91  526.98*