HIEU, Nguyen; 						PHAI, Vu Van; 						HOWARD, Limbert.
 Cave systems in Phong Nha - Ke Bang area.
<strong>VNU Journal of Science: Earth and Environmental Sciences</strong>, [S.l.], v. 28, n. 4, dec. 2012.
ISSN 2588-1094.
Available at: &lt;<a href="https://js.vnu.edu.vn/EES/article/view/1555" target="_new">https://js.vnu.edu.vn/EES/article/view/1555</a>&gt;. Date accessed: 29 apr. 2024.