Perhaps you should try some spelling variations:
kho tang » cao tang
hieu ve » hieu va, hieu van
dinh vi » dinh ve, dinh viet, dinh tri
truc va » thuc va, thuc vat, trung va
su sach » so sach, vu sach
lap hai » lap tai, lap lai, lap hoat
ky sang » ky nang, ky dang, ky tang
ve cau » ke cau, va cau, ve cac
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 ((ky sang) or (kho tang)) lap hai. hieu ve cau truc va ((hanh vi) or (dinh vi)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky sang) OR (kho tang)) lap hai. hieu ve cau truc va ((hanh vi) OR (dinh vi)) cua te.
• Adding a wildcard symbol may retrieve word variants: su sach ((ky sang) or (kho tang)) lap hai. hieu ve cau truc va ((hanh vi) or (dinh vi)) cua te*.