Perhaps you should try some spelling variations:
thuc tuan » thu tuan, thuc huan, thuc luan
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
tu cach » tu cac
su sach » so sach, vu sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
cua tre » cuu tre, cua triet, dua tren
anh vi » hanh vi, anh va, anh ve
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: ((tu cach) or (su sach)) ky lang xa hoi. hieu van nam thuc tuan anh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (su sach)) ky lang xa hoi. hieu van nam thuc tuan anh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (su sach)) ky lang xa hoi. hieu van nam thuc tuan anh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky lang xa hoi. hieu van nam thuc tuan anh vi ((cua tre) OR (cua te))*.