Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
qua tham » qua cham, qua than, qua thanh
tham luc » than luc, tham nuoc, tham thuc
te sach » toc sach
ty lang » tay lang, ty xang, ty hang
lang xa » lang ha, dang xay, lang van
va hang » van hang, va nang, va lang
hang vi » hang va, hanh vi, hang di
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
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: ((te sach) or (doc sach)) ty lang xa hoi. hieu qua tham luc va hang vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ty lang xa hoi. hieu qua tham luc va hang vi cua te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ty lang xa hoi. hieu qua tham luc va hang vi cua te*.