Perhaps you should try some spelling variations:
doc sach » toc sach, nuoc sach, dac sac
hoc sach » hoc sinh, hoc cac, hoc anh
tham luc » than luc, tham nuoc, tham thuc
qua tham » qua cham, qua than, qua thanh
te sach » toc sach
hang vi » hang va, hanh vi, hang di
va hang » van hang, va nang, va lang
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
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) OR (hoc 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) OR (hoc sach)))) ty lang xa hoi. hieu qua tham luc va hang vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (((doc sach) OR (hoc 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) OR (hoc sach)))) ty lang xa hoi. hieu qua tham luc va hang vi cua te*.