I don't think there is one list of all LPC credits because LPC content is continually expanding. However, there are a few options that may help:

• The Universal LPC Spritesheet Generator is regularly updated and maintains a credits list of all assets it uses. However, it only uses character assets. This list would NOT include credits for terrain, items, etc.\
• Your Downloads list has a feature at the bottom "Download Credits File" to generate a credits file for every asset you've downloaded: Here is the credits file from your downloads as of the time of this posting. However, it my include credits for non-LPC assets that you have downloaded. It also would NOT include any attribution for LPC assets you downloaded while not signed-in.
• That same auto-credit file generation feature is present for all collections, not just the auto-generated download collection. There are several LPC collections, but none of them contain all LPC assets. This is because different collectors have different opinions about what should qualify or not, or they have not added the newer content to their collections, or they have several separate collections for the sake of categorization: LPC [TOWNS], LPC [WEAPONS] etc. However, making your own collection is easy. In fact, you could create a collection and add all the LPC assets to-date just by searching for the tag "LPC" and selecting your new collection in the "Collect into..." dropdown on the search tool (see attached screenshot). Or you could manually curate your collection so it only contains the LPC content you consider "official" or "useful for Fracture". 

Let me know if you have any questions.