ATMEGA168 Microcontrollers: Features, Pinout, and Datasheet
Arduino Uno Rev 3 Pinout, ATMega168/328 Pin Mapping, Schematics, EAGLE Files, and More! - Documents - Arduino - element14 Community
Pololu - Arduino pin mapping for the ATmega168.
Amazon.com: Dorhea Pro Mini 168 Mini ATMEGA168 5V/16MHz Electronics Development Module Compatible with Nano Microcontrol Micro Control Board : Electronics
Amazon.com: Pro Mini Atmega168 Mini ATMEGA168 Crystal Oscillator Board Module 16M 5V for Arduino Nano Replace Atmega328 : Electronics