Nordström, G. (1918). "On the Energy of the Gravitational Field in Einstein's Theory". Verhandl. Koninkl. Ned. Akad. Wetenschap., Afdel. Natuurk., Amsterdam. 26: 1201–1208. Bibcode:1918KNAB...20.1238N.
"NORDSTRÖM Gunnar"(PDF). List of faculty at the university of Helsinki. Helsinki University Central. (I have chosen to use this source when conflicting information was available in less official sources, mainly regarding graduation years)