https://bg.wikipedia.org/wiki/%D0%AF%D1%82
Буквата Ят

https://bg.wikipedia.org/wiki/%D0%A0%D1%83%D1%81%D0%BA%D0%B0_%D1%80%D0%B5%D0%B4%D0%B0%D0%BA%D1%86%D0%B8%D1%8F_%D0%BD%D0%B0_%D1%81%D1%82%D0%B0%D1%80%D0%BE%D0%B1%D1%8A%D0%BB%D0%B3%D0%B0%D1%80%D1%81%D0%BA%D0%B8%D1%8F_%D0%B5%D0%B7%D0%B8%D0%BA
Руска_редакция_на_старобългарския_език

https://ru.wikipedia.org/wiki/%D0%9A%D0%B8%D1%80%D0%B8%D0%BB%D0%BB_%D0%A2%D1%83%D1%80%D0%BE%D0%B2%D1%81%D0%BA%D0%B8%D0%B9 – Кирилл_Туровский
https://bg.wikibooks.org/wiki/Старобългарска_литература

–