Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
dang xay » dang van, van xay
hoc sach » hoc sinh, hoc cac, hoc anh
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va nang » van nang, da nang, cam nang
nang di » nang du, hang di, nang ji
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: ((toc sach) or (hoc sach)) _ ((lang xa) or (dang xay)) hoi. hieu va cac duc va nang di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) _ ((lang xa) OR (dang xay)) hoi. hieu va cac duc va nang di cua te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) _ ((lang xa) or (dang xay)) hoi. hieu va cac duc va nang di cua te*.