Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu hanh » thuc hanh, thu thanh, thuy hanh
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
hanh xa » hanh va, hanh ma, hanh xu
hieu ve » hieu van
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
lam va » nam va, dam va, lam ha
thiet » thieu

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 thu hanh xa hoi. ((hieu ve) or (hieu va)) cam xuc ((va hanh) OR (van hanh)) lam va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu hanh xa hoi. ((hieu ve) OR (hieu va)) cam xuc ((va hanh) OR (van hanh)) lam va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu hanh xa hoi. ((hieu ve) or (hieu va)) cam xuc ((va hanh) OR (van hanh)) lam va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach thu hanh xa hoi. ((hieu ve) or (hieu va)) cam xuc ((va hanh) OR (van hanh)) lam va thiet*.