Odd English transliteration in Marcuse (who misinterprets it as a name of the entire instrument) and Podnos, who oddly defines it as a "variable drone", referring to Kachulev (Иван Качулев, »Български духови двугласни народни музикални инструменти« (1965)), but also mentions it, oddly, in his Index I (Bagpipe names), thus confusingly also suggesting it to be a name of the entire instrument; NB: ➺ Ručalo.