Solar activity / Einar Tandberg-Hanssen. Tandberg-Hanssen, E. (Einar), 1921- Solar activity. 523.7 TAS Bibliography: p. 409-444. Waltham, Mass. : Blaisdell Publishing, 1967. 1967. 1967 Text xv, 464 p. : eng A Blaisdell book in the pure and applied sciences