Reduction of unstressed central and back vowels in Contemporary Standard Bulgarian. - Mitko Sabev (ICPhS, 2015)

Bulgarian Unstressed Vowel Reduction: Received Views vs Corpus Findings. - Mitko Sabev; Bistra Andreeva; Christoph Gabriel; Jonas Gruenke (INTERSPEECH, 2023)

Unstressed vowel reduction and contrast neutralisation in western and eastern Bulgarian: A current appraisal. - Mitko Sabev (J. Phonetics, 2023)