DUCATI8.NET: A site with all info about the ducati 8 series:
Ducati 1988 851 Tricolore Superbike Strada and Superbike "kit"
Ducati 1989-1992 851 Strada
Ducati 851 Sport Productions: 1989 851 SP1, 1990 851 SP2, 1991 851 SP3
Ducati 1993-1994 888 Strada
Ducati 888 Sport Productions: 1992 888 SP4, 1992 888 SP4S (SPS), 1993 888 SP5
Ducati 888 SPO (Sport Production Omologato): 1993 SPO, 1994 SPO Ltd.