Perhaps you should try some spelling variations:
thu sac » thu sach, thu san, thu xac
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu ve » hieu van
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
sac ky » cac ky, sai ky
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky lang xa hoi. ((hieu ve) or (hieu va)) pham duc va danh vi ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky lang xa hoi. ((hieu ve) OR (hieu va)) pham duc va danh vi ((cua tu) OR (cua su))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky lang xa hoi. ((hieu ve) or (hieu va)) pham duc va danh vi ((cua tu) OR (cua su))*".