Improvement of heavy-heavy current for calculation of B̅ → D(*)lv̅ form factors using Oktay-Kronfeld heavy quarksJon A. Bailey, Yong-Chull Jang, Weonjong Lee and Jaehoon LeemEPJ Web Conf., 175 (2018) 14010DOI: https://doi.org/10.1051/epjconf/201817514010