McKeown’s Guide to Classic and Historic Cameras lists Semmendinger cameras as part of their price guide.

Lind’s List, which is also a price guide, also lists various Semmendinger camera models.

The Western Photographs of John K. Hillers: Myself in the Water references August Semmendinger’s cameras on page 20:

“In 1875 W.H. Jackson lugged such a monster, probably a Semmindinger (sic.) ‘mammoth plate’ wet-collodion camera, up and down the canyons and mesas of southwestern Colorado while he photographed landscapes and ‘Cliff Dweller’ archaeological sites.”

The Bergen County (New Jersey) Board of Chosen Freeholders published a book titled Bergen County Panorama in 1941. This book makes a cursory reference to August Semmendinger on page 104:   

“August Semmindinger’s (sic) photographic laboratories in Fort Lee were experimenting with an enterprise which soon was to revolutionize the habits of the country.”

August Semmendinger is not specifically mentioned in the book Images of America: Fort Lee, but his camera making plant is referenced on page 25:

“There was a small photographic manufacturing plant on Gerome Avenue.”

This reference is to the Semmendinger plant which was located on Eickhoff Street (also spelled Ichoff Street) which was later renamed Gerome Avenue.

In 1881, a book titled the Photographic Times and American Photographer edited by J. Traill Taylor states the following about the Semmendinger camera:

“The idea of utilizing that portion of the camera just under the lens and converting it into a sort of cupboard, is, at least, novel. To A. Semmindinger (sic) belongs the full credit of this idea; whether photographers will appreciate it is another matter. But, seriously, it may become handy for storing away a sandwich, a few screws, or – anything else.”

In Cartes de Visite In Nineteenth Century Photography by William C. Darrah, 1981,  Semmendinger is mentioned and credited as one of the early American inventors of the multiplying camera. 

“Another American, August  Semmendinger, patented a four lens camera with repeating back in July 1861.”

A book by Robert C. Post in 1976 outlining the 1876 Centenntial titled (in short), A Treatise Upon Selected Aspects of the Great International Exhibition held in Philadelphia… not only mentions August Semmendinger as an exhibitor in Photography Hall, but includes a picture of one of his cameras:

“230/A plate camera with bellows  made around 1875 by August Semmendinger of Ft. Lee, New Jersey, an exhibitor in Photography  Hall.”

Craig’s Daguerreian Registry by John S. Craig, 1994, mentions August in Volume 3:

“Camera patentee and  manufacturer.. 1860 and later.  Semmendinger was issues a patent covering camera manufacture on February 21, 1860. He was issued a second patent for another camera  apparatus on August 7, 1860.”