Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
su triet » su viet, su tien, ve triet
tu cong » thu cong, te cong, tai cong
vu cham » va cham, vu kham, tu cham
va hanh » van hanh, va thanh, va danh
tu nong » tu dong, tu tong, tu tuong
hieu vu » hieu va, hieu ve, hieu su
ve su » va 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 sach ((tu nong) OR (tu cong)) xa hoi. hieu vu cham duc ((va hanh) or (gia thanh)) ve su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((tu nong) OR (tu cong)) xa hoi. hieu vu cham duc ((va hanh) OR (gia thanh)) ve su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((tu nong) OR (tu cong)) xa hoi. hieu vu cham duc ((va hanh) or (gia thanh)) ve su triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ((tu nong) OR (tu cong)) xa hoi. hieu vu cham duc ((va hanh) or (gia thanh)) ve su triet*.