New York, NY: Bell Telephone Laboratories, Incorporated April, 1950. first collected edition. , 155 pages. Self wrappers. Blue cloth spine over stapled printed grey, black and blue wrappers. 5 hole punched at spine as issued. Several tears to the thin blue cloth at the spine, corner creases. Light browning overall. Reading creases to covers. Previous owner name (R. Warner, 1-118) inked on front cover. Minor edgewear, otherwise a nice copy.
A (presumed) later state, printed on non-glossy paper stock and bulking 9.4 mm thick. "Issued April, 1950" inside the rear wrapper. This later state has reset covers, and the illustration lower right is different (the transistor icon touches the outside of the circle in three places and is simplified, where on the first state it does not touch the circle edges at all). This example retains 6.6 mm (approx 14 inch) punch holes (another later state we've examined has slightly larger holes). Good. Wraps. 
Collects a number of important transistor related papers from the Bell System Technical Journal, Vol 28, pp. 335-489, July 1949. Reprints "Hole Injection in Germanium - Quantitative Studies and Filamentary Transistors", "Some Circuit Aspects of the Transistor", "Theory of Transient Phenomena in the Transport of Holes in an Excess Semiconductor", "On the Theory of the A-C Impedance of a Contact Rectifier", and "The Theory of p-n Junctions in Semiconductors and p-n Junction Transistors." Plus an editorial note regarding semiconductors.
COLLECTORS NOTE: The Bell System Monograph series is not an offprint series although it is often incorrectly referred to in this manner. It was rather a publication of Bell Telephone Laboratories used to widely distribute (primarily to libraries and large corporations) research articles written by Bell System employees in a variety of widely dispersed publications (including but certainly not limited to the Bell System Technical Journal). The series therefore represents a much broader selection of Bell System research than the Bell System Technical Journal did. Collectors prize this series as they are often (but not always) the first separate appearance of a paper and hence are the closest one can get to the elusive and ever sought after offprint.