Heavy-quark meson spectrum tests of the Oktay–Kronfeld action Jon A. Bailey, Carleton DeTar, Yong-Chull Jang, Andreas S. Kronfeld, Weonjong Lee and Mehmet B. Oktay Eur. Phys. J. C, 77 11 (2017) 768 Published online: 15 November 2017 DOI: 10.1140/epjc/s10052-017-5266-y