Please try to make a brief introduction on Bulgarian SF history.
There is a debate which is the first Bulgarian SF work.
Probably the best-known candidate is Bulgarian mainstream writer Ivan Vazov (Иван Вазов; 1850-1921) with his story “The Last Day of the XX century” („Последният ден на ХХ век“; 1899) where, as the title suggests, he described a prosperous Bulgaria hundred years in the future. Furthermore, he wrote a poem “In the Kingdom of the Fairies” („В царството на самодивите“; 1884) that could easily be called a fantasy.
The second contender is the mysterious author of Veda Slovena („Веда Словена“; 1874-1881). Originally published by Stephan Verkovich (Стефан Веркович; 1821-1893) as folk tales from the Rhodope Mountains area, collected by Ivan Gologanov (Иван Гологанов; 1839-1895) over a period of twelve years. Gologanov worked as a teacher in that area. The content of the book, describing pagan gods and pre-Islamic/pre-Christian myths, cast doubts about its authenticity. Today many scientists consider it a literary hoax, written by Gologanov himself.
Some people think Svetoslav Minkov (Светослав Минков; 1902-1966) was the first Bulgarian SF writer because of his fantastic and diabolic works from the 1920s. He certainly started the Bulgarian horror genre. Minkov was also a co-founder, together with Vladimir Polyanov (Владимир Полянов; 1899-1988) of Argus (“Аргус”; 1922), the first publishing house in the world specialized exclusively in speculative fiction.
Finally, there is the great body of Bulgarian folk tales, but those are usually considered precursors of the fantastic genre. In the end, it doesn’t really matter if SF&F started a decade earlier or later; all the candidates for the title of the first Bulgarian SF&F writer contributed to the rich and diverse genre that we all love so much today.