Betrieb und Bedienung von ortsfesten Viertakt-Dieselmaschinen. 1920, S. Sygall.; Dalog, A., (Ikke digitaliseret)
The practice of lubrication. An ingineer-ing treatise on the origin,. nature and testing of lubricants, their selection, application and use. 1920, (Ikke digitaliseret)
Sweden as producer of woodgoods,pulp,paper, tar, and other forest-products. Stockholm, Svenska teknologforeningens f.orlag,1920. 1920, (Ikke digitaliseret)
Dansk Handelsleksikon : Handelsret, Handelsudtryk, Valuta, Bank, Børs, Forsikring, Aktievæsen, Handel, i alle Former og Varer 1920, Nielsen, Charles V.
Hand- und Hülfsbuch zur Ausführung physiko-chemischer Messungen. 1920, Ostwald, W.; Luther, R., (Ikke digitaliseret)