This may be UK only, would be very grateful if anyone can check on other Kindle stores.

Noticed that you can buy Findegil's The J. R. R. Tolkien Companion and Guide for £15 on the Kindle, all three volumes.

If you download the computer Kindle App (Mac, PC), you can search the text on your computer ?

https://www.amazon.co.uk/J-Tolkien-Companion-Guide-Chronology-ebook/dp/B073TRKLB7/ref=sr_1_2?dchild=1&qid=1590754232&refinements=p_27%3AWayne+G.+Hammond&s=digital-text&sr=1-2&text=Wayne+G.+Hammond
https://www.amazon.co.uk/J-R-Tolkien-Companion-Guide-ebook/dp/B073TR7RJ9/ref=sr_1_3?dchild=1&qid=1590754232&refinements=p_27%3AWayne+G.+Hammond&s=digital-text&sr=1-3&text=Wayne+G.+Hammond
https://www.amazon.co.uk/J-R-Tolkien-Companion-Guide-ebook/dp/B073TRDWXP/ref=sr_1_4?dchild=1&qid=1590754232&refinements=p_27%3AWayne+G.+Hammond&s=digital-text&sr=1-4&text=Wayne+G.+Hammond