Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
va thanh » gia thanh, ban thanh, va tinh
va hanh » van hanh, va danh, ban hanh
tai cua » thai cua, tai cuc, tri cua
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
cao tuc » dao tuc, cao duc, cao suc
va cao » va cac, va co, va dao
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) or (doc sach)) ky tang xa hoi. hieu va cao tuc ((va hanh) or (va thanh)) tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky tang xa hoi. hieu va cao tuc ((va hanh) OR (va thanh)) tai cua te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky tang xa hoi. hieu va cao tuc ((va hanh) or (va thanh)) tai cua te*.