Ola Björling (aka citrus or ukiro) is a Doom level designer and texture artist. His work includes The Darkening Episode 2, Overload DM, Venom and the two Tantrum maps. Ola was voted as the community's fifth favorite mapper as part of Doomworld's 5 years of Doom celebration.
- The Talosian Incident (1997)
- Venom (1998)
- Tantrum 2 (1998)
- The Darkening Episode 2 (2000)