Perhaps you should try some spelling variations:
thieu nien » thien nhien
lang van » dang van, tang van, hoang van
van hanh » van thanh, ban hanh, van anh
nien cac » vien cac, dien cac, bien cac
ve triet » va trien, su triet
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
cac toc » cac toi, cac nuoc, cac thoi
toc van » hoc van, toc san, tac van
su viet » so viet
su sach » so sach, vu sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((nang xa) or (lang van)) hoi. thieu nien cac toc van hanh vi ((su viet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (lang van)) hoi. thieu nien cac toc van hanh vi ((su viet) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (lang van)) hoi. thieu nien cac toc van hanh vi ((su viet) or (ve triet))*.