Collaborative work, social communications and information systems : proceedings of the IFIP TC8 working conference on collaborative work, social communications and information systems, COSCIS '91, Helsinki, Hanasaari, Finland, 27-29 August 1991 / ed. by R.K. Stamper ... [et al.]Sijthoff & Noordhoff series on information systems / consulting editors: Richard J. Welke [and] Ronald K. Stamper