Não informado. (2020). Records. Geological Survey Department.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Records. Georgetown: Geological Survey Department, 2020.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Records. Geological Survey Department, 2020.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.