Não informado. (1981). Health technology directions. Program for Appropriate Technology.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Health Technology Directions. Seattle, Wash: Program for Appropriate Technology, 1981.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Health Technology Directions. Program for Appropriate Technology, 1981.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.