single or double belt lines between furnaces? - Factorio Forums
Steel furnace - Factorio Wiki
Factorio Prints: Mk1 Mid-Game Furnace
Electric Furnaces vs Steel Furnaces - Factorio Forums
Smelting and Furnace Ratios - Factorio Tutorial - YouTube
Design / Blueprint] Stone/Steel furnace block design suitable for early and mid-game. This design is intended to achieve maximum compression in 0.16, after the loss of the underground belt compression trick. :
Factorio": How to Build a Furnace/Smelting Setup - LevelSkip
Optimal Furnace Array Length : r/factorio
Steam Community :: Guide :: Factorio - Everything To Do With Smelting: Belt & Bot Based