Perhaps you should try some spelling variations:
vu khanh » vu thanh, van khanh, duy khanh
te sach » toc sach
sach ky » sac ky, sach y, sach ty
hieu vu » hieu va, hieu ve, hieu su
truc va » thuc va, trung va
dan dau » danh dau, doan dau, van dau
dau cuu » dau cua, dau cuoi
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ((xa hoi) or (ma hoa)). hieu vu khanh ((truc va) OR (thuc vat)) dan dau cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((xa hoi) OR (ma hoa)). hieu vu khanh ((truc va) OR (thuc vat)) dan dau cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((xa hoi) or (ma hoa)). hieu vu khanh ((truc va) OR (thuc vat)) dan dau cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((xa hoi) or (ma hoa)). hieu vu khanh ((truc va) OR (thuc vat)) dan dau cuu tre*.