I suspect I have performed an incorrect amendment (B') of last commit (B), which cause all my work in the last commit (B) gone.
  A
  |
  B [master]
amend to 
     A
   / |
  B  B'
    [master]
I think if I haven't do any git gc, my original "correct" commit (B) should still in the repository. However, because it is not referred directly/indirectly by any ref, I cannot find it out. Is there any way that I can list out such kind of "unreferred" commit in git so that I can retrieve my work from that commit?
Thanks
 
    