Spicules and Macrospicules: Simultaneous Hα and He II (304 Å) Observations Georgakilas, A. A. ; Dara, H. ; Zachariadis, Th. ; Alissandrakis, C. E. ; Koutchmy, S. ; Delannée, C. ; Delaboudinière, J. -P. ; Hochedez, J. -F. Abstract Publication: Three-Dimensional Structure of Solar Active Regions Pub Date: 1998 Bibcode: 1998ASPC..155..376G