Perhaps you should try some spelling variations:
te sach » toc sach
su sach » so sach, vu sach
cao hoa » cao hoat, cao khoa, cau hoa
hieu ve » hieu va, hieu van
cac bac » cac bai, cac ban, cac cach
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, dua tren
ve cac » va cac, vien cac
bac va » ban va, bac ha, bao va
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: ((te sach) or (su sach)) ky nang cao hoa. hieu ve cac bac va hanh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (su sach)) ky nang cao hoa. hieu ve cac bac va hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (su sach)) ky nang cao hoa. hieu ve cac bac va hanh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (su sach)) ky nang cao hoa. hieu ve cac bac va hanh vi ((cua tre) OR (cua te))*.