1. Chapman, S., , and J., Barrels, , , Geomagnetism, , 2 vols., xxviii+1049+ pp., Oxford University Press, , 1940, . (The lunar magnetic variations are discussed in chapters 5, 8, 19, 20, and 23.)
2. Terrestrial magnetism and electricity, , edited by J. A., Fleming, , , (Phys cs of the Earth, vol. VIII), xii+ pp., McGraw-Hill Book Company, , New York and London, , 1939, .
3. Chapman, S., , J. C. P., Miller, , Mon. Not. R. Astr. Soc., Geophys. Sup., 4, 649-669 1940,
4. Barrels, J., , and H. F., Johnston, , , Trans. Amer. Geophys. Union, 1940, 273– -287 , 1940, .
5. Geophysikalischer Mondalmanach;Bartels;Zs. Geophysik,1937