Raspberry Pi announces the availability of 64-bit operating system and it's ready for download - Electronics-Lab.com
Raspberry Pi 3 has 64-bit CPU, but 32-bit Raspbian OS (for now)
Raspberry Pi: New 'glorious' 64-bit operating system is available to install | ZDNET
Raspberry Pi – Compiling a Module for the 64-bit Kernel | Zak's Electronics Blog ~*
Install Raspberry 64 OS - Q-engineering
Make Your Raspberry Pi 4 Faster with a 64 Bit Kernel #PiDay #RaspberryPi @Raspberry_Pi « Adafruit Industries – Makers, hackers, artists, designers and engineers!