Perhaps you should try some spelling variations:
sach kem » hanh kem
nang cau » nang cao, hang cau, nang dau
sach ky » sac ky, sach ty, sach hay
hieu va » lieu va, hieu qua
cao tuc » dao tuc, cao duc, cao suc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((((sach ky) or (sach kem))) or (sach y)) nang cau hoi. hieu va cao tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((((sach ky) OR (sach kem))) OR (sach y)) nang cau hoi. hieu va cao tuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((((sach ky) or (sach kem))) or (sach y)) nang cau hoi. hieu va cao tuc va hanh vi cua tre*.