“…Even the early treatments [15][16][17] predict the masses of many hadrons with good accuracy. Among the recent treatments there are extensive developments of the traditional approach [18,19], calculations using the method of hyperspherical harmonics [20], solving the Faddeev equations [21], variational calculations [22][23][24], nonrelativistic calculations using quarkdiquark approximation [25,26], etc. Relativistic effects are taken into account by building up the relativistic quark models based on approximate solution of the Bethe-Salpeter equation [27], or using quark-diquark approximation to simplify relativistic dynamics [28][29][30].…”