@matchakitkat Thank you for the suggestion. We do ask, and require, that an MCAT-specific source citation be included with any and all content-related suggestions, in order to streamline the process of suggestions and deck maintenance. More information can be found here: AnKing MCAT Deck Submission Guidelines
Please let me know if you have any other questions. 
This info is all from other cards in the deck. I’m always kind of split on these summary extra sections where we include the basis of three other cards in the deck. I’m not sure how to weigh the value of having all of this relevant info in the card versus potentially disrupting rating these other cards if they come up in the same review sessions. Seems like it comes up a lot and maybe we should try to become up with a position/standard for it.