Two indispensable books, both published by
Museum “Schloss Moyland”. 

If there’s one book interested readers should know of (besides the older reference books treating Rembrandt’s drawings, sketches, etchings etc…) it is the (bi-lingual) Museum Schloss Mayland (2005) book: Rembrandt and the English Painter-Etchers. It can be obtained (new-used) through most international & internet bookselling sites at ridiculously low price. 

“Bartsch” (B…) catalogue numbers for Rembrandt’s landscape etchings: a great help to help identify. The numbers without a picture are the later dismissed (not an original design by Rembrandt) etchings.