Knudsen, Ivar (1914). "A Smokeless Marine". The American—Scandinavian Review. 2 (1). American—Scandinavian Foundation: 21–28. Retrieved 3 October 2014.
"Motorship Progress". Pacific Marine Review. 19 (4). Pacific American Steamship Association / Shipowners' Association of the Pacific Coast: 201. April 1922. Retrieved 3 October 2014.