Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
va thuat » ky thuat, ki thuat, va thuc
te sach » toc sach
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
va cham » va chat, va tham
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
xuc va » duc va, tuc va, luc va
di cua » dai cua, doi cua, de 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 cham) or (va thuat)) xuc va hang di 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 cham) OR (va thuat)) xuc va hang di cua te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ty nang xa hoi. hieu ((va cham) or (va thuat)) xuc va hang di cua te*.