Such a weird lens: Mir-1B 37mm F2.8 (with K-1): Pentax SLR Talk Forum: Digital Photography Review
Russian White A Semi-Wide Angle Lens Mir-1 37mm F2.8 Is the Exceptional Among Copy Lenses, Especially Its User-Friendliness - Wabi Sabi Tokyo with Old Lenses. Hidekatsu Street Photo
Using a MIR-1 37mm f2.8 Lens on M42, need help! info in comments : r/VintageLenses
lightseeker.org / Lichtsucher.com: MIR-1 with 37mm f/2.8 "Grand Prix" Brussels 1958 - uncommon in many ways