Vasmer, Max (1964–1973) “упова́ть”, in Oleg Trubachyov, transl., Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), Moscow: Progress
Trubachyov, Oleg, editor (2002), “*obpъvati”, in Этимологический словарь славянских языков [Etymological dictionary of Slavic languages] (in Russian), numbers 29 (*obpovědati – *obsojьnica), Moscow: Nauka, →ISBN, page 47
^ Snoj, Marko (2016) “ȗpati”, in Slovenski etimološki slovar [Slovenian Etymology Dictionary] (in Slovene), 3rd edition, https://fran.si: “Pslovan. *upъva̋ti”
^ Olander, Thomas (2001) “-pъvati: -pъvajǫ -pъvajetь”, in Common Slavic Accentological Word List[1], Copenhagen: Editiones Olander: “a håbe (PR 134)”