Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
doi cua » dai cua, hoi cua, dong cua
sai ky » sac ky
va cam » va cham, va cac, va cao
cua te » cua tu

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 y) or (sai ky)) nang xa hoi. hieu va cam thuc ((va hanh) or (van hanh)) doi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach y) OR (sai ky)) nang xa hoi. hieu va cam thuc ((va hanh) OR (van hanh)) doi cua te.
• Adding a wildcard symbol may retrieve word variants: su ((sach y) or (sai ky)) nang xa hoi. hieu va cam thuc ((va hanh) or (van hanh)) doi cua te*.