Fotografías de Pexels (licencia Pexels: uso libre, comercial incluido). / Photos from Pexels (Pexels license).

hero-refinery: https://www.pexels.com/photo/aerial-view-of-an-industrial-plant-with-lights-turned-on-during-night-time-10407684/
field-tower: Barbara Reis — https://www.pexels.com/photo/workers-repairing-a-cell-tower-19728112/
command-center: Fernando Narvaez — https://www.pexels.com/photo/advanced-control-room-in-el-agustino-lima-32529341/
oilfield: jayjay13 — https://www.pexels.com/photo/a-pumpjack-extracting-oil-out-of-an-oil-well-16133914/
edge-site: Barnabas Davoti — https://www.pexels.com/photo/a-cell-tower-9290873/