I made a chart of the Existing Pokémon Type Combinations! (Updated) : r/ pokemon

A chart with what type combinations are missing and an example for each comb there is already - 9GAG

Every Unused Pokémon Type Combination

Pokemon: 5 Unused Type Combinations That Should Be In Future Games (& 5 That Shouldn't)

Every Pokémon With A Unique Type Combination

Pokemon Franchise Still Has 9 Unused Type Combos After Scarlet and Violet

Pokémon: These Type Combinations Still Aren't Used

Fantastic Fakemon — fakemon: This is my updated list of unused type

What Pokemon types have the least weaknesses? - Quora

Unused Combination Types

Roxanna Rambles — celesteela: Unused type combinations for Pokémon