Amazon.com: ACEIRMC for Arduino Nano V3.0, Nano Board CH340/ATmega328P Without USB Cable, Compatible with Arduino Nano V3.0 ( Without Cable) (3 Pack) : Electronics
ATmega328P | Microchip Technology
Atmega328P without Arduino PCB Design - Share Project - PCBWay
Standalone Arduino with ATMEGA328P / Serial working, but serial programming not (only once after buning bootloader) - Arduino Stack Exchange
ATMEGA328P FUSE RESET - Instructables
ATmega328/P Introduction Feature
Nano 3.0 Micro-Controller ATMEGA328P with I / O Expansion Shield Arduino – Envistia Mall
Where can I find a hardware manual (or documentation) for Arduino Uno & ATMega328P? - Arduino Stack Exchange