1. Wasserfall, K. F., , , The horizontal component of magnetic intensity at Oslo Observatory, 1843–1930 (daily values for 09 and 14 o'clock), , Geofys. Pub., , Oslo, , 13, , (No. 2) ( 1941, ).
2. Magnetic horizontal intensity at Oslo, 1843–1930;Wasserfall;Terr. Mag.,1941
3. Declination at Oslo, 1843–1930;Wasserfall,1941