Tip: If you don't know the exact author's name right now, you can just leave it blank!
Start with KRKB search. If the book is not there, search public book sources, then use manual entry only when both searches miss.
Use this when the book already appears in KRKB. Choose one result, then add it to the selected shelf.
Try this when KRKB search misses the book. Choose the best match, then KRKB can fill in details in the background.
Selected book
Use this when public-source search still misses. Add an ISBN, or add the title and author.