Source is labeled "Source:" to the left. The artist is "Karasuma Tasuku" as indicated by the red colored tag in the tag list. If you want their artist site, click on the '?' next to the tag, and you will be presented with links to both their personal site, and their pixiv account.
You probably should check all those things before asking for sources that are already provided.
What I'd like to know is why Aerith has a different weapon, but Cloud still has the B-Sword (not to mention Yuffie's looks like her initial equip., too).
