Los puntos clave no están disponibles para este artículo en este momento.
The number of volumes of lecture notes produced over the years based on material presented at summer schools in high energy physics is surprisingly large. The quality of these publications has been disappointingly variable; but it is pleasant to report that the present work, containing lectures delivered in 1973 at the Scottish Universities' summer school, is of a uniformly high standard.
B H Bransden (Sat,) studied this question.