Visibility of Earth-Directed Coronal Mass Ejections Michels, D. J. ; Howard, R. A. ; Koomen, M. J. ; Plunkett, S. ; Brueckner, G. E. ; Lamy, Ph. ; Schwenn, R. ; Biesecker, D. A. Abstract Publication: Fifth SOHO Workshop: The Corona and Solar Wind Near Minimum Activity Pub Date: 1997 Bibcode: 1997ESASP.404..567M