Welsh, Matt; Dalheimer, Matthias Kalle; Kaufman, Lar (1999). "1: Introduction to Linux". Running Linux (3rd ed.). Sebastopol, California: O'Reilly Media, Inc. p. 5. ISBN1-56592-976-4. OCLC50638246.
Welsh, Matt; Dalheimer, Matthias Kalle; Kaufman, Lar (1999). "1: Introduction to Linux". Running Linux (3rd ed.). Sebastopol, California: O'Reilly Media, Inc. p. 5. ISBN1-56592-976-4. OCLC50638246.