(2020). 集邮博览．2020,no. 9-12.
Chicago Style aipamena集邮博览．2020,no. 9-12. 2020.
MLA aipamena集邮博览．2020,no. 9-12. 2020.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.
APA aipamena
(2020). 集邮博览．2020,no. 9-12.
Chicago Style aipamena集邮博览．2020,no. 9-12. 2020.
MLA aipamena集邮博览．2020,no. 9-12. 2020.