Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
sach tu » sach thu, cach tu, sach ty
cao suc » cao su, cao duc
qua cao » qua cac, qua ca, qua cai
nang xa » lang xa, nang ma, mang xa
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 tu ((nang xa) or (nang x)) hoi. hieu qua cao suc ((va danh) OR (va dinh)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu ((nang xa) OR (nang x)) hoi. hieu qua cao suc ((va danh) OR (va dinh)) vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu ((nang xa) or (nang x)) hoi. hieu qua cao suc ((va danh) OR (va dinh)) vai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach tu ((nang xa) or (nang x)) hoi. hieu qua cao suc ((va danh) OR (va dinh)) vai cua te*.