I. Introduction page -- I. Some examples -- 2. The aims of an investigation of congestion -- 3. The arrival pattern -- 4. The service mechanism -- 5. The queue-discipline -- 6. The measurement of congestion -- 7. The investigation of queueing systems -- 8. The modification of queueing systems -- II. Some simple queues with random arrivals -- 1. Introduction -- 2. Statistical equilibrium -- 3. Single-server queue with random arrivals and exponential service-times -- 4. Arrival rates and service-times dependent on queue size -- 5. Further remarks on equilibrium conditions -- 6. Single-server queue with random arrivals and general distribution of service-times -- 7. The busy-period distribution -- III. More about simple queues -- 1. Non-equilibrium theory -- 2. Queues with many servers -- 3. Queues with priorities -- IV. Machine Interference -- l. Statement of problem -- 2. The simplest probability model -- 3. Some complications -- V. More specialized topics -- I. Introduction -- 2. The method of stages -- 3. The integral equation of a single-server queue -- 4. Simulation and Monte Carlo methods -- 5. Series of queues -- 6. The busy-period distribution -- Appendixes -- I. Bibliographical notes -- I I. Exercises and further results -- III. Notes on the theory of probability and Laplace-Stieltjes transforms -- Author Index -- Subject Index.