This volume contains the lectures presented at an Advanced Study Institute on "Magnetic Resonance Techniques in Fossil Energy Problems," which was held at the village of Maleme, Crete, in July of 1983. As of this writing, a different popular attitude prevails from that when the ASI was proposed as far as how critical the world energy picture is. In the popular press, a panglossian attitude (the "petroleum glut" of the 80's) has replaced the jeremiads of the 70's ( a catastrophic "energy crisis"). Yet, there are certain important constants: (a) for the foreseeable future, fossil energy sources (petroleum, coal, oil shale, etc. ) will continue to be of paramount importance; and (b) science and technology of the highest order are needed to extend the fossil ener~y resource base and to utilize it in a cost-effective manner that is also environmentally acceptable. It is precisely this second item that this volume addresses. The volume introduces the phenomenology of magnetic resonance ~n a unified and detailed manner, starting from the behavior of spins in a magnetic field and proceeding to a density matrix consideration of the phenomena involved. The various important parameters of NMR and EPR are discussed in detail, as well as their significance and the information that may be obtained from their proper consideration. Advanced topics are then considered, including line-broadening interactions, coherent averaging and multiple quantum methods in NMR, ENDOR, electron spin echoes, dynamic nuclear polarization. problems of quantifi­ cation, 2-Dimensional N}1R, Mossbauer, and instrumentation.