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