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
sach tu » sach thu, cach tu, sach uu
toi van » thi van, tri van, doi van
cac toi » cac thoi
nang xa » lang xa, nang ma, mang xa
sach ty » sach y, sach thu, xach tay
vi ve » va ve, gi ve, ve ve

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 tu) OR (sach ty)) ((nang xa) or (nang x)) hoi. thieu nien cac toi van hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach tu) OR (sach ty)) ((nang xa) OR (nang x)) hoi. thieu nien cac toi van hanh vi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach tu) OR (sach ty)) ((nang xa) or (nang x)) hoi. thieu nien cac toi van hanh vi ve triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach tu) OR (sach ty)) ((nang xa) or (nang x)) hoi. thieu nien cac toi van hanh vi ve triet*.