Perhaps you should try some spelling variations:
thieu nien » thien nhien
ve triet » va trien, su triet
van hanh » van thanh, ban hanh, van anh
nien cac » vien cac, dien cac, bien cac
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
sach ty » sach y, sach tu, sach thu
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 xa)) 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 xa)) hoi. thieu nien cac toc van hanh vi ((su viet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang xa) OR (lang xa)) 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 xa)) hoi. thieu nien cac toc van hanh vi ((su viet) or (ve triet))*.