On 21st August I got not only a postcard but also a cover from Slovenia.
Slovene Ships - Ljubljana (issued 25-05-2018)
Birds of Slovenia (from set of five) (issued 29-05-2015)
Inside was a mint Slovenian souvenir sheet about the World Bee Day (issued 25-05-2018). To highlight the role of bees and other pollinators for the ecosystem, the 20th May was declared as World Bee Day in 2018. It was proposed by Slovenia and the 20th May was chosen, as Anton Janša, the pioneer of beekeeping, was born on this day in 1734.
Thank You very much Nusa!