@book{467919,
  address    = {Lima},
  pages      = {50},
  publisher  = {Ministerio de Educación Pública},
  title      = {Cálculo 4},
  url        = {http://www.sil.org/americas/peru/show_work.asp?id=20570},
  year       = {1954},
  country    = {Peru [PE]},
  lgcode     = {Spanish [spa]},
  macro_area = {Eurasia},
  sil_id     = {20570},
  src        = {sil16},
  subject    = {Arithmetic [Zarth]}
}