Information hiding : 4th international workshop, IH 2001, Pittsburgh, PA, USA, April 25-27, 2001 : proceedings / Moskowitz, Ira S., Computer security Data protection 005 SPR 2001 C154 Or. Berlin ; New York : Springer, c2001. c2001. Text viii, 412 p. : http://link.springer-ny.com/link/service/series/0558/tocs/t2137.htm