Eurodict: Bulgarian-English dictionary & multilingual
Sa: Bulgarian-English dictionary
Dictionary of the
Bulgarian language (Речникъ на блъгарскый языкъ) by Najden Gerov (Найден Геров)
(1895)
А-Д - Е-К - Л-О - П - Р-Ю & supplément
Complete Bulgarian-English
dictionary by Constantine Stephanove (1914)
online translation: Bulgarian-English & other languages & web page
Bulgarian-English translation to translate a small
text
Bulgarian keyboard to type a text with the Cyrillic alphabet
Bulgarian conversion : Cyrillic <> Latin characters
pronunciation of the Bulgarian alphabet & basic phrases
(with sound)
Bulgarian grammar, pronunciation with sound, basic vocabulary
Short grammar of the
Bulgarian language, with reading lessons, by William Morfill (1897)
Grammar of
the Bulgarian language by C.F. Morse (1859)
Bulgarische Grammatik:
Bulgarian grammar by Gustav Weigand (1917) 
books about Bulgarian language: Google
books & Internet
archive
Bulgarian literature
Bulgarian
texts with translation of words in English
books about Bulgarian literature: Google
books & Internet
archive
Chansons populaires
bulgares: Bulgarian folk songs, by Auguste Dozon (1875)
the Bible in Bulgarian (Библия):
several versions in Bulgarian (with sound), English, Greek, Latin
Всички хора се раждат свободни и равни по достойнство и права.
Те са надарени с разум и съвест и следва да се отнасят помежду си в дух на братство.
First article in many languages
Declaration of Human Rights in Bulgarian, Russian, English & other languages