Heavy quarkonia
  Two complementary approaches to the theory of heavy quarkonia are discussed. The nonrelativistic potential models give amazingly accurate predictions, but lack a theoretical justification. The expansion in powers of $v/c$ is theoretically very acceptable, but is not as good in giving numerical predictions. The importance of combining these two approaches is stressed. 
Kacper Zalewski (Jagellonian University and Institute of Nuclear   Physics, Krak\'ow)