Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
thanh di » thanh doi, thanh de, thanh do
sach van » sach han, sach va, bach van
thuc day » thuc dan, thuc vat
su sach » so sach, vu sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
di cua » dai cua, doi cua, de cua
ve cac » va cac, vien cac
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: su sach van ((nang xa) or (nang ma)) hoi. hieu ((ve cac) or (va cao)) thuc day thanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van ((nang xa) OR (nang ma)) hoi. hieu ((ve cac) OR (va cao)) thuc day thanh di cua te.
• Adding a wildcard symbol may retrieve word variants: su sach van ((nang xa) or (nang ma)) hoi. hieu ((ve cac) or (va cao)) thuc day thanh di cua te*.