Inhaltsangabe1.Introduction.- 2.Quasi-stationary Distributions: General Results.- 3.Markov Chains on Finite Spaces.- 4.Markov Chains on Countable Spaces.- 5.Birth and Death Chains.- 6.Regular Diffusions on [0,8).- 7.Infinity as Entrance Boundary.- 8.Dynamical Systems.- References.- Index.- Table of Notations.- Citations Index.