Sure! Here are some resources on COOL grammar:
1. Naver Blog: This blog post provides information about COOL grammar and its three-volume series. It includes a concise and practical explanation of grammar concepts, various types of grammar problems, and exercises to help students improve their English grammar skills. You can find more information at the following link: Naver Blog
2. Aladin: This website offers the COOL Grammar series for purchase. The series includes three books that cover essential grammar topics for middle school students. Each book provides explanations, answers, and exercises to help students master grammar concepts. You can find more information and purchase the books at the following link: Aladin
Please note that the information provided is based on the sources mentioned above.