Ablikim, M., Achasov, M.N., Ahmed, S., Yuncu, A., “Measurements of the Branching Fractions for the Semileptonic Decays D-s(+) -> phi e(+)v(e), phi mu(+)v(mu), eta mu(+)v(mu) and eta 'mu(+)v(mu)“, Physical Review D, 97, 1, 2018.