Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
lang xa » lang ha, dang xay, lang van
hieu ve » hieu van
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
tuc van » thuc van, truc van, tuc va
y lang » o lang, _ lang, tay lang
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y lang xa hoi. ((hieu ve) OR (hieu va)) cam tuc van hanh vi ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y lang xa hoi. ((hieu ve) OR (hieu va)) cam tuc van hanh vi ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y lang xa hoi. ((hieu ve) OR (hieu va)) cam tuc van hanh vi ((cua te) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. ((hieu ve) OR (hieu va)) cam tuc van hanh vi ((cua te) or (cua tu))*.