The source files of the latest version of Tiberium Tale - at least the version worked on the last time (about 11 months ago). "ALL_tpls" folder contains many assets that were left uncredited in the mod simply because they aren't used. However, if you'd like to use any of them, first you need to find these who own them, and credit them properly. Some units such as Nod Piranha are the work of the mod's main author, so you don't actually need to credit anybody or even the mod (and also if you make any derivative works based on them). Everything else in ALL_tpls folder is a property of respective owners - so it's rather recommended to avoid using assets from that folder altogether.