first secular Bulgarian book
... that the first secular Bulgarian book of the modern era was an 1824 children's encyclopedia?
... that the <b id="mwDgw"><a href="./Primer_with_Various_Instructions" id="mwDg0" rel="mw:WikiLink" title="Primer with Various Instructions">first secular Bulgarian book</a></b> of the modern era was an 1824 children's encyclopedia?