Probing the mass and structure of the Ring Nebula in Lyra with SOFIA/GREAT observations of the [CII] 158 micron line
Journal article published in 2012 by
R. Sahai,
Mr Morris 
,
Mw Werner,
R. Güsten,
H. Wiesemeyer,
G. Sandell
,
Mw Werner,
R. Güsten,
H. Wiesemeyer,
G. Sandell
