Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
lam thuc » lam thuoc, am thuc, nam thuc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
ky lang » ky nang, ky dang, ky tang
ha hoi » hoa hoi, ha noi, va hoi
vi cua » vai cua, di cua
va lam » van lam, va lap

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 lang ((ha hoi) OR (xa hoi)). hieu va lam thuc ((va hanh) or (va thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((ha hoi) OR (xa hoi)). hieu va lam thuc ((va hanh) OR (va thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((ha hoi) OR (xa hoi)). hieu va lam thuc ((va hanh) or (va thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ((ha hoi) OR (xa hoi)). hieu va lam thuc ((va hanh) or (va thanh)) vi cua tre*.