You need to be more specific. "Mary" is probably the author's first name. Without knowing the title of the book and the author's full name, I doubt that anyone can help you.
Title of book is " mathematical methods in physical science" and the author is Mary .L.Boas
Why did you post a thread asking for help pirating a book? You wasted more time posting this here, then it would have taken you to find it by yourself. How'd you find this site if you don't know how to use Google?
I Google it and downloaded some files which were supposed to be that book but it was full of 400 to 500 empty pages!
No, we're not going to help you pirate a book. Wanna buy it? Here's a link