Bl1:Alzghool, Inkpen, 2007
Bl2:Amati, Van Rijsbergen, 2002
Bl3:Oard, Soergel, Doermann, Huang, Murray, Wang, Ramabhadran, Franz, Gustman, 2004
Bl4:Oard, Wang, Jones, White, Pecina, Soergel, Huang, Shafran, 2007
Bl5:Ounis, Amati, Plachouras, He, Macdonald, Johnson, 2005
Bl6:Pecina, Hoffmannov´a, Jones, Zhang, Oard, 2007
Bl7:Salton, Buckley, 1988
Bl8:Shaw, Fox, 1994