Perhaps you should try some spelling variations:
chinh tai » chinh tri
toc sach » hoc sach, doc sach, thuoc sach
sach van » sach han, sach va, bach van
van lang » van nang, va lang, van hang
lang xa » lang ha, dang xay, lang van
cam tuc » cam xuc, nam thuc, dam thuc
cam tu » cam thu, nam tu, dam tu
cua te » cua tu

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