Disponible en: https://books.google.com.mx/books?id=0KksqC7ymJcC&printsec=frontcover&dq=economia&hl=es419&sa=X&ved=0ahUKEwjK7sD_1ajaAhVqxoMKHXfUD68Q6AEIRTAF#v=onepage&q=factor%20&f=false [7 Abr.