Shri Ramakrishna Math publication - Madras India.  6th Impression  Hardback  Translated to English by Swami Nikhilananda.  With notes, comments and introduction.  These books were originally paperback versions produced in India. But the book blocks were actually stitched booklets - just as hardback books have – but with a flimsy soft cover. We bought many new copies (lots of spares) some years ago for use with a study group. Some of the copies (the ones on Ebay) were never used. So they are new. But those which were used deteriorated very quickly when handled due to the lack of a hard back.  When we decided to sell, the flimsy paper-back seemed too bad to sell, so we had the remaining new unused ones made into a hard back by a book binder, who can do that kind of thing.  The front and any inserts stuck onto the hard cover (inside) are from the original flimsy soft cover, they are of the quality provided by the Indian publisher.  They do vary in quality due to both the original paper covers (reused as labels onto the hardback) and that they are made into hardback individually by hand (not machine done). The inside book block is the original new book. The hard cover is also new - so really all is like a new book - they were never use by anyone - only left on a bookshelf and never opened to read them - until the book binder did his bit. Publishers in India are a bit slapdash in the production of their books hence there is variation in the quality of the original flimsy paper cover which we have reused.