Here is Practical Problems in Mathematics for Heating & Cooling Technicians by Dr. Russell B. DeVore. 4th Edition. Part of Delmar’s Practical Problems in Mathematics Series. From Thompson Delmar Learning. Bottom corner shows light curling(see photos). Otherwise the book is in good condition. Tight binding with no loose, missing or torn pages. a few pages have a crease from being folded at one time. Buyer pays Standard Shipping. I am pretty reasonable so if you are interested, make an offer. Thank you.