Perhaps you should try some spelling variations:
thuoc sac » thuoc sach, thuoc dac, thuoc sai
van hanh » van thanh, ban hanh, van anh
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve giao » te giao, viet giao, van giao
va danh » va dinh, va dan, va hanh
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
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: thuoc sac ky ((nang x) or (lang xa)) hoi. hieu ve giao duc ((van hanh) or (va danh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sac ky ((nang x) OR (lang xa)) hoi. hieu ve giao duc ((van hanh) OR (va danh)) hai cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sac ky ((nang x) or (lang xa)) hoi. hieu ve giao duc ((van hanh) or (va danh)) hai cua tre*.