Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
dao hanh » dao thanh, dang hanh, ban hanh
thuc dao » thuc dan, thuc day, chuc dao
nam thuc » nam thuoc, am thuc, nam thu
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nang ra » nang ma, lang ra, nang ro
nang co » nang cao, nang doc, nang noi
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 quang nam thuc dao 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 quang nam thuc dao 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 quang nam thuc dao hanh vi ((cua tu) or (cua su))*.