Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
nang van » dang van, tang van, lang van
cac thuc » cach thuc, can thuc, cay thuc
tu sach » thu sach, su sach, te sach
danh di » danh du, xanh di, danh dien
van hoc » van hoa
sach ky » sac ky, sach y, sach ty
cac thu » cach thuc, cac thoi
cua tre » cuu tre, cua triet, dua tren
va danh » va dinh, va dan, va hanh
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 sach ky nang van hoc. hieu vien ((cac thuc) OR (cac thu)) va danh di ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang van hoc. hieu vien ((cac thuc) OR (cac thu)) va danh di ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang van hoc. hieu vien ((cac thuc) OR (cac thu)) va danh di ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang van hoc. hieu vien ((cac thuc) OR (cac thu)) va danh di ((cua tre) or (cua te))*.