Testing the tetraquark structure for the X resonances in the low-lying regionHungchong Kim, K. S. Kim, Myung-Ki Cheoun, Daisuke Jido and Makoto OkaEur. Phys. J. A, 52 7 (2016) 184DOI: https://doi.org/10.1140/epja/i2016-16184-0