Ola Björling (aka citrus or ukiro) is a Doomer known for his maps and textures. His work includes The Darkening Episode 2, Overload DM, Venom and the two Tantrum maps. Ola was voted as the community's fifth favourite mapper as part of Doomworld's 5 years of Doom celebrations.
- The Talosian Incident (1997)
- Venom (1998)
- Tantrum 2 (1998)
- The Darkening Episode 2 (2000)