"Doublet", Neutron and Neutron stars --- An essay on Landau and Neutron   stars
  The concept of extremely dense matter at supra-nuclear density was first speculated by L. Landau in the beginning of 1930s when neutron was just discovered. A historical review on these issues not only explains the interaction between micro and cosmic physics, but also has profound implications for scientific innovation. It is surely meaningful in realistic physics education to look back to this history. (The review was published in Chinese.) 
Renxin Xu (PKU)
physics.gen-ph