Thanh, T.
(1993).
 Về phân loại bản đồ du lịch.
<em>VNU Journal Of Science: Natural Sciences And Technology, 9</em>(4).
Retrieved from <a href="https://js.vnu.edu.vn/NST/article/view/4247" target="_new">https://js.vnu.edu.vn/NST/article/view/4247</a>