MacLane, S. (1971). Categories for working mathematician (Vol. 5). Springer-Verlag. 
@book{MacLane2,
  title = {Categories for working mathematician},
  author = {MacLane, S.},
  year = {1971},
  publisher = {Springer-Verlag},
  series = {Graduate texts in {M}athematics},
  volume = {5}
}