(2019). 环 球．2019,no.13,17,20-21,23-25.
Chicago Style aipamena环 球．2019,no.13,17,20-21,23-25. 2019.
MLA aipamena环 球．2019,no.13,17,20-21,23-25. 2019.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.
APA aipamena
(2019). 环 球．2019,no.13,17,20-21,23-25.
Chicago Style aipamena环 球．2019,no.13,17,20-21,23-25. 2019.
MLA aipamena环 球．2019,no.13,17,20-21,23-25. 2019.