Não informado. (1979). Working paper series. International Potato Center, Social Science Department.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Working Paper Series. Lima: International Potato Center, Social Science Department, 1979.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Working Paper Series. International Potato Center, Social Science Department, 1979.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.