13. High-energy heavy-ion collisions and quark-gluon plasma. 13.1. Nuclear stopping power and the baryon content. 13.2. Bjorken's estimate of the initial energy density in high-energy nucleus-nucleus collisions. 13.3. Hydrodynamics of the quark-gluon plasma -- 14. Signatures for the quark-gluon plasma (I). 14.1. Dilepton production in the quark-gluon plasma. 14.2. Dilepton production from other processes. 14.3. Spectrum of dileptons -- 15. Signatures for the quark-gluon plasma (II). 15.1. Debye screening in the quark-gluon plasma. 15.2. J/[symbol] suppression in the quark-gluon plasma. 15.3. Experimental information on J/[symbol] production and J/[symbol] suppression. 15.4. J/[symbol] suppression in hadron environment. 15.5. Transverse momentum distribution of J/[symbol] particles -- 16. Signatures for the quark-gluon plasma (III). 16.1. Photon production in the quark-gluon plasma. 16.2. Photon production by quark-antiquark annihilation. 16.3. Photon production by q[symbol] annihilation in the plasma. 16.4. Photon production by the Compton process. 16.5. Photon production in the plasma due to the Compton process. 16.6. Photon production by hadrons. 16.7. Photon production by parton collisions. 16.8. Experimental information on photon production -- 17. Signatures for the quark-gluon plasma (IV). 17.1. The Hanbury-Brown-Twiss effect of intensity interferometry. 17.2. Pion momentum correlations from chaotic sources. 17.3. Coherent and partially coherent sources. 17.4. Experimental information on pion interferometry -- 18. Signatures for the quark-gluon plasma (V). 18.1. Strangeness content in matter at thermal and chemical equilibrium. 18.2. Rate of approach to chemical equilibrium in a quark-gluon plasma. 18.3. Experimental information on strangeness production -- 19. Summary