Solar PhysicsFebruary 1974, Volume 34, Issue 2, pp 507–508 | Cite asBook reviewsAuthorsAuthors and affiliationsC. de JagerA. BruzekArticle 20 Downloads This is a preview of subscription content, log in to check access.Copyright information© D. Reidel Publishing Company 1974Authors and AffiliationsC. de Jager1A. Bruzek21.The Astronomical Institute at UtrechtThe Netherlanda2.Fraunhofer Institute at FreiburgFreiburgGermany