Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cham duc » pham duc, cham soc, pham duy
sach ky » sac ky, sach y, sach ty
hang vi » hang va, hanh vi, hang di
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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 ky nang ma hoi. ((hieu ve) OR (hieu va)) cham duc van ((hoang kim) or (hang vi)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. ((hieu ve) OR (hieu va)) cham duc van ((hoang kim) OR (hang vi)) su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. ((hieu ve) OR (hieu va)) cham duc van ((hoang kim) or (hang vi)) su triet*".