* The name is misspelled. There may be a slight error in the spelling. Could you double-check?
* The author is not widely known. It's possible that Sandra Ryan is a newer author or one who writes in a specific niche that isn't widely recognized.
* The author has a different writing name. Some authors use pen names.
Could you provide more information, such as the genre the author writes in, any specific book titles, or any other details that might help identify the author?