Quick answer — Kazuma Kamachi worked on A Certain Scientific Railgun T (Original Story), A Certain Scientific Railgun S (Original Story), A Certain Scientific Railgun (Original Story) and 12 more anime.
Kazuma Kamachi worked on A Certain Scientific Railgun T (Original Story), A Certain Scientific Railgun S (Original Story), A Certain Scientific Railgun (Original Story), A Certain Magical Index II (Original Creator), A Certain Magical Index: The Miracle of Endymion (Original Creator), Toaru Kagaku no Railgun: Misaka-san wa Ima Chuumoku no Mato Desukara (Original Story), A Certain Magical Index (Original Creator), A Certain Scientific Accelerator (Original Story) and 7 more.