Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
duc manh » suc manh, duc anh, duc minh
va cham » va chat, va tham
hanh ki » hanh vi, hanh ky, hanh kien
duc van » duc va, duc tan, duc phan
sach tu » sach thu, cach tu, sach ty
nang xa » nang x, lang xa, nang ma
sach va » sach xa, sach ha, sach dao
hieu va » lieu va, hieu qua
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach tu) or (sach va)) nang xa hoi. hieu va cham ((duc van) OR (duc manh)) hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach va)) nang xa hoi. hieu va cham ((duc van) OR (duc manh)) hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tu) or (sach va)) nang xa hoi. hieu va cham ((duc van) OR (duc manh)) hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach va)) nang xa hoi. hieu va cham ((duc van) OR (duc manh)) hanh ki su triet*.