Perhaps you should try some spelling variations:
sach duoc » sach dao, sach dung, sinh duoc
sach nuoc » cac nuoc, bach tuoc, dich nuoc
hanh tai » thanh tai, hang tai, han tai
cau treo » cau theo, cau tren, cau triet
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
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 va ((sach nuoc) OR (sach duoc)) va hanh tai ((cua tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu va ((sach nuoc) OR (sach duoc)) va hanh tai ((cua tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu va ((sach nuoc) OR (sach duoc)) va hanh tai ((cua tre) or (cau treo))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu va ((sach nuoc) OR (sach duoc)) va hanh tai ((cua tre) or (cau treo))*.