Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
san viet » gian viet, anh viet
sach thu » sach thue, sach thieu, sach tham
thu lang » thu hang, thu bang, phu lang
hieu van » thien van, lieu va, hieu ve
va viet » hoa viet, mai viet, dao viet
luc lap » luc lam, tuc lap, luc luan
tu sach » thu sach, su sach, te sach
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van

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 lang xa hoi. ((hieu van) or (hieu va)) cam luc lap trinh vat ((va viet) or (san viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu lang xa hoi. ((hieu van) OR (hieu va)) cam luc lap trinh vat ((va viet) OR (san viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach thu lang xa hoi. ((hieu van) or (hieu va)) cam luc lap trinh vat ((va viet) or (san viet))*.