Institute of Mathematics
Vietnam Academy of Science and Technology
18 Hoang Quoc Viet Road
10307 Hanoi
Vietnam
Center for Mathematics and its Applications (CEMAT)
Instituto Superior Técnico
Av. Rovisco Pais 1049-001 Lisboa
Portugal
E-mail: thanhan_at_math.ac.vn, thanhan_at_math.ist.utl.pt
Web:
http://vie.math.ac.vn/~thanhan/