APA (7. basım) Alıntı
Associated Collectors of El Salvador & Freer, B. P. El Salvador Postal Stationery Handbook: Section 1 - Postcards.
Chicago Style (17. basım) Atıf
Associated Collectors of El Salvador ve B. Phillips Freer. El Salvador Postal Stationery Handbook: Section 1 - Postcards.
MLA (9th ed.) Atıf
Associated Collectors of El Salvador ve B. Phillips Freer. El Salvador Postal Stationery Handbook: Section 1 - Postcards.
Uyarı: Bu alıntı herzaman %100 doğru olmayabilir..