‘Abbott Elementary’ Sets Crossover Episode With ‘It’s Always Sunny in Philadelphia’ - Variety

1. ‘Abbott Elementary’ Sets Crossover Episode With ‘It’s Always Sunny in Philadelphia’  Variety
2. It’s Always Sunny Takes a Field Trip to Abbott Elementary  Vulture
3. "Abbott Elementary," "It's Always Sunny in Philadelphia" tease crossover episode on social media  CBS News
4. ‘Abbott Elementary’ To Cross Over With ‘It’s Always Sunny In Philadelphia’ In Season 4  Deadline
5. ‘Abbott Elementary’ and ‘It’s Always Sunny in Philadelphia’ Creators Confirm Crossover Episode  Us Weekly