@TechReport{ hilty.ea:usage:2005, author = {M. Hilty and A. Pretschner and T. Walter and C. Schaefer}, institution = {DoCoMo Euro-Labs Internal Technical Report}, language = {USenglish}, month = {December}, number = {I-ST-015}, title = {Usage Control Requirements in Mobile and Ubiquitous Computing Applications}, year = 2005, user = {pretscha} }