Spectral dynamics of nonequilibrium phonons in ruby / Maarten Jeroen van DortPhonons in submicron geometries / Robert Jan van WijkStimulated emission of phonons in ruby / Petrus Adrianus FokkerCoherent phonon avalanches / Paul Alexander van WalreeStimulated phonon emission and dynamics of near-zone-boundary phonons in optically pumped ruby / door Johannes Gerardus Maria van Miltenburg