@misc{116086,
  pages      = {54},
  title      = {Guía de enseñanza 2: Cálculo},
  url        = {http://www.sil.org/americas/peru/show_work.asp?id=20538},
  year       = {1960},
  country    = {Peru [PE]},
  lgcode     = {Spanish [spa]},
  macro_area = {Eurasia},
  sil_id     = {20538},
  src        = {sil16},
  subject    = {Arithmetic [Zarth], Teacher's guides [Ztgd]}
}