This appears as paper #14 (of 7 papers by Schwinger) of the 34 collected papers in his classic reference Selected Papers on Quantum Electrodynamics (1958).
Schwinger349. This appears as paper #14 (of 7 papers by Schwinger) of the 34 collected papers in his classic reference "Selected Papers on Quantum Electrodynamics" (1958). Schwinger was awarded the Nobel Prize in 1965 along with Feynman and Tomonaga "for...fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles". "Following the establishment of the theory of relativity and quantum mechanics, an initial relativistic theory was formulated for the interaction between charged particles and electromagnetic fields. However, partly because the electron's magnetic moment proved to be somewhat larger than expected, the theory had to be reformulated. Julian Schwinger solved this problem in 1948 through "renormalization" and thereby contributed to a new quantum electrodynamics."--Nobelprize.org