Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
dang mau » dong mau, dang van, dang su
vien dai » hien dai
dang ma » dang mam, dang mat, tang ma
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
o viet » so viet, hoc viet
vi o » vi mo, vi do, voi o

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach thieu ((dang ma) or (dang mau)) hoi. hieu vien dai ((xuc van) or (duc van)) hanh vi o viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thieu ((dang ma) OR (dang mau)) hoi. hieu vien dai ((xuc van) OR (duc van)) hanh vi o viet.
• Adding a wildcard symbol may retrieve word variants: toc sach thieu ((dang ma) or (dang mau)) hoi. hieu vien dai ((xuc van) or (duc van)) hanh vi o viet*.