Season 8 rank up requirements : r/TheSilphArena
Pokemon GO: Full List of Level-Up Rewards - Gameranx
All Pokémon GO level up rewards and requirements, 1-50
Pokémon Go level requirements, level up item rewards list
Pokémon GO: How To Level Up (Your Trainer) Like A Pro
Experience - Bulbapedia, the community-driven Pokémon encyclopedia
Pokémon Go level requirements, level up item rewards list
Pokémon Go Power up PokéStops: How to power up PokéStops or Gyms
Australian Level 40+ Test Report: Level up requirements, Platinum
XP requirements for Levels so far (1-25+) : r/TheSilphRoad