@book{johnston1919,
  address   = {Oxford},
  author    = {Johnston, Harry H.},
  note      = {2 vols},
  pages     = {840},
  publisher = {Oxford University Press},
  title     = {A Comparative Study of the Bantu and Semi-Bantu Languages},
  url       = {https://archive.org/stream/comparativestudy01johnuoft#page/iii/mode/1up},
  year      = {1919/22}
}