  Recent results obtained by the COSY-11 collaboration concerning the
production of eta and eta' mesons in the pp --> pp Meson reaction are
presented. A comparison of the production amplitude for the pi(0), eta and eta'
mesons at the same phase space volume allows to conclude that the proton-eta'
interaction is in the order of, or smaller than, the proton-pi(0) one. A total
cross section determined in a preliminary analysis of the data of elementary
kaon and antikaon production via the pp-->ppK(+)K(-) reaction measured at
excess energy of Q = 17 MeV is reported.
