@book{gSchadebergUmbundu,
  author    = {Schadeberg, Thilo C.},
  pages     = {61},
  publisher = {Cologne: Rüdiger Köppe},
  series    = {Grammatische Analysen Afrikanischer Sprachen},
  title     = {A Sketch of Umbundu},
  volume    = {1},
  year      = {1990}
}