1. The silver disk pyrheliometer;Abbot;Smithsonian Misc. Coll.,1911
2. An improved water-flow pyrheliometer and the standard scale of solar radiation;Abbot;Smithsonian Misc. Coll.,1932
3. Das Ångströmsche Kompensationspyrheliometer und die pyrheliometrische Skala;Ångström;Meteor Zscht.,1914
4. The Ångström Compensation pyrheliometer and the pyrheliometric scale;Ångström;Astrophysical Journal,1914
5. Comparisons between pyrheliometers and on the difference between the Ångström and Smithsonian standard;Ångström;Monthly Weather Rev.,1919