Answer: personal letters written during a previous century
Explanation: Letters between friends or acquaintances, if written during a past era, would provide more inspiration for a fiction writer than scientific articles or encyclopedia entries, which provide limited, very objective information.
I know quite a bit about it. I do suggest trying a no fear Shakespeare b/c it translates all of it to modern english. <u>https://www.sparknotes.com/nofear/shakespeare/romeojuliet/</u>