Top 10 Problems on Massive Stars
  We have asked a number of researchers to compile their lists of the top 10 problems in the field of massive stars. This paper is a compilation of these lists. We attempted to survey observers and theorists and those studying all evolutionary stages in the lives of massive stars. Each list reflects the proposer's personal point of view, but hopefully, this compilation will motivate new young astronomers and begin a new series of discussion. 
Cassio Barbosa (1) and Donald Figer (2) ((1) IAG-USP, (2) STScI)