Nancy Drew: Treasure in the Royal Tower - Detailed walkthrough with screenshots and puzzle solutions. - http://www.justadventure.com/Walkthroughs/TallyHo/Walkthroughs/Nancy%20Drew/Treasure%20in%20the%20Royal%20Tower/ND4.htm
Quandary Reviews - Reviewed by Steve Ramsey and 12-year-old Emily. "It was really fun playing it! At times I got a bit confused, but once I thought about it and went over it I knew just what I needed to do." Includes screenshots. - http://www.quandaryland.com/jsp/dispArticle.jsp?index=398
UHS: Treasure in the Royal Tower - Select questions from the game and view hints in increasingly detailed steps, from gentle nudges to full answers. - http://www.uhs-hints.com/uhsweb/ndrew4.php