Extended powers and H? ring spectra.- Miscellaneous applications in stable homotopy theory.- Homology operations for H? and Hn ring spectra.- The homotopy theory of H? ring spectra.- The homotopy groups of H? ring spectra.- The adams spectral sequence of H? ring spectra.- H? ring spectra via space-level homotopy theory.- Power operations in H ? d ring theories.- The mod p k-theory of QX.