Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang co » nang cao, nang doc, nang noi
nang ra » nang ma, lang ra, nang ro
qua cac » cua cac
cac tuc » cac toc, cac tu, cac tac
xa hanh » xa thanh, xa khanh, va hanh
cua tu » cua tuc, cua cu, cua te
cua su » qua su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang co) or (nang ra)) hoi. hieu qua cac tuc xa hanh vi ((cua tu) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang co) OR (nang ra)) hoi. hieu qua cac tuc xa hanh vi ((cua tu) OR (cua su)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang co) or (nang ra)) hoi. hieu qua cac tuc xa hanh vi ((cua tu) or (cua su))*.