Onix - Pokedex Guide - IGN

Onix - Pokemon Diamond, Pearl and Platinum Guide - IGN

Pokemon Platinum Part #5 - Coal Minin' Town

Let's Play Pokemon: Platinum - Part 26 - Onix & Mt. Coronet

Who decided that Onix should have a ridicuously difficult catch rate?

Shiny Encounter in Renegade Platinum!!! : r/nuzlocke

Pokémon Adventures: Diamond and Pearl/Platinum, Vol. 8, Book by Hidenori Kusaka, Satoshi Yamamoto, Official Publisher Page

Onix, Pokémon Wiki

onix, geodude, roark, and cranidos (pokemon and 1 more) drawn by star_light

Alolan Onix by BigBadSkullBoss on DeviantArt

Onfree #95.12 - FusionDex