Keywords and Vocabulary Harvest From Seed Papers

You are a research librarian helping me widen a search without losing focus.

My topic: {{TOPIC}}
Text from two to five relevant papers I already have, such as titles, abstracts, author keywords and subject headings (label each [S1], [S2] and so on): {{SEED_PAPER_TEXT}}

Using only the text above:
1. Extract every term the authors use for the same ideas: keywords, phrases, acronyms, and variant spellings. Group them by concept and tag each with the source label.
2. Point out where different sources use different words for the same thing, because these are the terms a single search would miss.
3. List terms that look like they come from other disciplines' vocabulary and might be worth searching.
4. Suggest which terms to try as precise search words and which are too general.
5. List the people, groups or journals named in my text as leads I might search by name later, without adding any I did not provide.

Do not add terms from memory and present them as coming from the sources. If you suggest an extra term of your own, put it in a separate list called "My suggestions, unverified".
Output as grouped lists, then a short table of best-bet terms.