The bad news first. Forget the 30% discount. 
Now the good news…..It is 40% off and no promo code needed! Holy smokes!
From Syngress:
“Now through August 15th, Elsevier is offering 40% off all their books, including X-Ways Forensics Practitioners Guide (use this link: http://store.elsevier.com/product.jsp?isbn=9780124116054&_requestid=665676). No promo code needed. Just follow the link, add to your cart and save big”
