org/licenses/by/2.5/bg/deed.enCC BY 2.5 bgCreative Commons Attribution 2.5 bgtruetrue English Souvenirsheet “10 Years of Bulgarian Antarctic Cartography”
https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse English Souvenirsheet Russian Малый марочный лист
org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse English Souvenirsheet Russian Малый марочный лист determination method: SHA-1