1. Supposed Propagation of equatorial magn. disturbances;Chree;Proc. Phys. Soc.,1910
2. Bauer, L. A., , R. L., Faris, , Terr. Magn., XV, S. 9 93, 219 1910,
3. Van Bemmelen, , , Appendix to Observations at Batavia, , XXIX, 1906,
4. Norwegian Aurora Polaris Expedition, 1902–3;Birkeland,1913
5. I Teil dieses Berichtes;Angenheister;Nachr. d. Kgl. Ges. d. Wiss. Göttingen,1913