Gaceta Nº 38.999 - 5.890, Njr
$2.00
Gaceta No. 37368, Rgraficas
$0.70
Sue Kay - Vaughan Jones, Macmillan
$1.00
Jorge E. Burbano Ruiz, Mcgraw Hill
$35.00
Oscar Pierre Tapia, Pierre Tapia
$6.00
Gaceta N. 38.763, Njr
$1.00
H. Gutierrez-r.de la Vara, Mcgraw Hill
$50.00