My Eastern Watch Collection: Seiko Prospex Green Sumo SPB103J1 (similar to SPB101J1) - Continuing the Tradition with Further Improvement Possible, A Review (plus Video)
Review of the Seiko Sumo SBDC001 | Book & Quote Monster
A Review of the Seiko Sumo: Heavyweight in the Dive Watches Arena - The Watch Company
Complete guide to the Seiko Sumo
Seiko Prospex Sumo SPB101J1 - YouTube
My Eastern Watch Collection: Seiko Prospex SFK003J1 Sea Sumo Solar GMT Green (similar to SFK001J1) - Additional Benefit of Solar and GMT, A Review (plus Video)