Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach kem » hanh kem
cam thuc » am thuc, nam thuc, cam thu
van hanh » van thanh, ban hanh, van anh
van cam » van nam, van lam, van cau
va hanh » va thanh, va danh, ban hanh
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky
di cuu » di cau, di cua, dinh cuu

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 kem) or (sac ky)) nang x ho. hieu van cam thuc ((va hanh) or (van hanh)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach kem) OR (sac ky)) nang x ho. hieu van cam thuc ((va hanh) OR (van hanh)) di cuu tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach kem) or (sac ky)) nang x ho. hieu van cam thuc ((va hanh) or (van hanh)) di cuu tre*.