PakCat catalogue record Tutorial, digital private branch exchanges (PBXs) By [edited by] Edwin R. Coover Bibliographic details ISBN0818608293 PublisherIEEE Computer Society Press Publication placeWashington, D.C. Publication year1989 Material typeBook Physical descriptionix, 384 p. Additional authorsCoover, Edwin R. SubjectsDigital electronics., Private branch exchange telephone equipment industry., Telephone switching systems, Electronic., Telephone