Jade: A Distributed Software Prototyping Environment. - Ian H. Witten; Graham M. Birtwistle; John G. Cleary; David R. Hill; Danny Levinson; Greg Lomow; Radford M. Neal; Murray Peterson; Brian W. Unger; Brian Wyvill (ACM SIGOPS Oper. Syst. Rev., 1983)

Understanding user goals in web search. - Daniel E. Rose; Danny Levinson (WWW, 2004)