Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cac nam » bac nam, cac ham, cai nam
cac cam » cad cam, cac cap, cac cau
va than » va thanh, van than, va phan
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
qua va » quan va, qua van, vua va
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu ((cac nam) OR (cac cam)) qua va than kinh ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ((cac nam) OR (cac cam)) qua va than kinh ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu ((cac nam) OR (cac cam)) qua va than kinh ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ((cac nam) OR (cac cam)) qua va than kinh ((cua tre) or (cuu tre))*.