@book{467950,
  address    = {Lima},
  pages      = {59},
  publisher  = {Ministerio de Educación},
  title      = {Cálculo 6},
  url        = {http://www.sil.org/americas/peru/show_work.asp?id=20810},
  year       = {1972},
  country    = {Peru [PE]},
  lgcode     = {Cashinahua [cbs]},
  macro_area = {South America},
  sil_id     = {20810},
  src        = {sil16},
  subject    = {Arithmetic [Zarth]}
}