Found this one from archive.org. Analysis of the different types of compressors available at the time.
Summary. This paper deals in a general way with volume compressors of the type used in sound recording. The subject matter is divided into six sections: the desirability of volume compression, compressor characteristics, problems arising from the use of compressors, classification of the types of compressors with the advantages and disadvantages of each type, compressor design, and the measurement of compressor performance.
