Ceiling from:
https://www.artstation.com/artwork/W24nVv
Tutorial available now, only on Arstation Learning:
https://www.artstation.com/learning/series/GD/creating-a-modular-sci-fi-environment
SBS & Sbar:
https://www.artstation.com/marketplace/p/MyMk/artstation-learning-scifi-ceiling-substance-graph