Gibson, Edward G. Quiet sun / - Washington D C : National Aeronautics and Space Administration, 1973. - xvii, 330 p. : ill. ; 25 cm. - National Aeronautics and Space Administration special publication 303 . Includes bibliographical references and Index. Subjects--Topical Terms: Space weatherSunspots -- ResearchHeliosphere Dewey Class. No.: 523.7 / GIB