Bomb vs atomic bomb

Bomb

noun
  • The atomic bomb; the capacity to launch a nuclear attack. 

atomic bomb

noun
  • The possession of one or more atomic bombs; the ability to launch a nuclear attack. 

  • A nuclear weapon that obtains its destructive energy from nuclear fission. 

How often have the words Bomb and atomic bomb occurred in a corpus of books? (source: Google Ngram Viewer )