The road to bringing K mount to birth was a long way | PENTAX official
Pentax 135mm f2.5 Takumar (Bayonet) – Kamerastore
File:Vintage Pentax ME Super 35mm SLR Camera, Aperture Priority, K Bayonet Mount, Made In Japan, Circa 1980 - 1986 (13364865963).jpg - Wikimedia Commons
PENTAX ASAHI TAKUMAR K (BAYONET) MOUNT 135MM F/2.5 TELEPHOTO PRIME LENS : Amazon.ca: Electronics
The Evolution of the Pentax K-mount - Articles and Tips | PentaxForums.com (Mobile)
Multi-Mount Lets You Use Bayonet Lenses on Your Pentax DSLR Without an Adapter | PetaPixel
Amazon.com : PENTAX ASAHI TAKUMAR K (BAYONET) MOUNT 135MM F/2.5 TELEPHOTO PRIME LENS : Slr Digital Cameras : Electronics