Can you pay a visit to TP library, search for a book (*)riddles(*).
It's a Big (about A3 sized) 2-3 inch thick, hardcover book. IIRC should be green/gray color (tho I can't remember a lot of details).
Can you get me the exact title and the ISBN and other publishing details.
To know you've got the right book. Open to the riddles index and search for riddles of the sphinx.... go to it and read it. The riddle are in rhymes and the answer is also in rhymes. In fact most of the riddles and answers are elegantly in rhymes.
I can't find it the NLB, and I forgotten the details of the book. It's one of the "must-have" book I want to buy.