You can order the books from the official homepage Klear Textbooks or via Coupang:
Integrated Korean: Beginning Level 1
Integrated Korean: Beginning Level 2
Integrated Korean: Intermediate Level 1
Integrated Korean: Intermediate Level 2
Integrated Korean Advanced Intermediate 1
Integrated Korean Advanced Intermediate 2
Integrated Korean: Advanced Level 1
Integrated Korean: Advanced Level 2
Integrated Korean: High Advanced Level 1
Integrated Korean: High Advanced Level 2
“이 글은 애드픽이 추천한 제품의 이용후기가 포함되었으며, 작성자에게 수수료가 지급됩니다.”
You may get a copy at Integrated Korean Advanced Intermediate 1 & 2 PDF (1st edition)