Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
qua ban » cua ban, qua quan
nam qua » nam quan, nam cua, nam mua
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky, sai ky

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 (sac ky)) nang ma hoi. ((hieu ve) or (hieu va)) nam qua ban thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang ma hoi. ((hieu ve) OR (hieu va)) nam qua ban thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang ma hoi. ((hieu ve) or (hieu va)) nam qua ban thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang ma hoi. ((hieu ve) or (hieu va)) nam qua ban thanh vai cua tre*.