New York: American Telephone and Telegraph Company 1949. First Edition. Two issues of the BSTJ April and July 1949. Both 8vo and publisher's original printed blue wrappers. Housed in a custom leather backed clam shell case. April 1949: -334 pages. Ink stamp: "Property of the Telephone Systems Training Section" on front wrapper and first page. Spine lightly faded and also slanted, otherwise bright and clean internally. July 1949: 335-600 pages. Previous owner name (N. Aron) inked on front wrapper and marked on rear panel. Spine sunned, wear to the extremities especially the head/tail of the spine panel. Overall light browning to the wrappers. Very Good. Wraps. 
Bardeen, Brattain and Shockley won the Nobel Prize in Physics in 1956 "for their researches on semiconductors and their discovery of the transistor effect." Bardeen's paper on A-C impedance is found in the July issue, and work by Shockley et al on Hole Injection in Germanium (pp 344-366 ; planned to be included in Holes and Electrons) as well as his own article on the Theory of p-N junctions in Semiconductors (pp 435-489). The April issue contains "Physical Principles involved in Transistor Action" by Bardeen and Brattain (pp 239-277), "the first comprehensive report on the transistor".
Together these key papers represent the discovery and initial work on the transistor, a seminal discovery in 20th century physics and the basis for most of today's electronics products.
There are also other papers on the transistor and semi-conductors, and papers by other Bell System researchers. The Bell System Research Labs functioned as a rich incubator during this period, turning out key developments across many technologies. The Bell System Technical Journal is an important journal of record for research in electronics, physics, communications theory, and mathematics.
Hook & Norman: Origins of Cyberspace, No. 450