Комментарии:EDT 331-332, VEWT 79, TMN 2, 358, ЭСТЯ 2, 185-188, Федотов 1, 442, Stachowski 66. Forms with o- may represent a different root (see *ol-tur-). On the other hand, the geographical distribution of this variant matches quite closely the change *b- > v- in a number of words with grammatical function (for Haladzh cf. vīer- 'give', vāor 'there is'), so most of the forms with o- may indeed reflect *bol- > *vol- > ol-; the different root *ol- is with more certainty reflected only in Middle Uyghur (At., Tefs., IM - cf. bar, bir- in the same sources) and Middle Kypchak (Bulgat, Ettuhf., see ЭСТЯ 2, 186).