This book gives a comprehensive review of the current status of the theory of the pion-two-nucleon systems at intermediate energies. It also makes an extensive comparison of the theoretical prediction with the corresponding data obtained recently from the major meson factories.Contents: Coupled πNN — NN Approach (PNNA)Nonrelativistic Three-Body TheoryRelativistic Three-Body EquationsThe Coupled NN — NΔ Approach (CCM)The Reaction NN → NNThe Reaction NN → πdThe Reaction NN → πNNThe Reaction πd → πdThe Reaction πd → πNNπNN Bound States and DibaryonsAppendices: The πN SubsystemThe NN SubsystemReadership: Nuclear physicists, especially medium energy physicists.Key Features:A single, easy-to-use resource detailing more than 60 different experiments over the past 20 years in heavy-ion induced secondary-particle productionAn accompanying includes a comprehensive set of data on experimental secondary-neutron production cross sections, thick-target yields, spallation products cross sections, and neutron yields behind shieldingContains detailed descriptions of the experiments and data analyses from all data setsParametrizations of the secondary-neutron data sets allow for a quick method to include the data in any computational application