Vector tetraquark state candidates: Y(4260 / 4220), Y(4360 / 4320), Y(4390) and Y(4660 / 4630) Zhi-Gang Wang Eur. Phys. J. C, 78 6 (2018) 518 Published online: 23 June 2018 DOI: 10.1140/epjc/s10052-018-5996-5
