Perhaps you should try some spelling variations:
su thanh » vu thanh, son thanh, cuu thanh
van hanh » van thanh, ban hanh, van anh
hai truc » dai truc, hai trac, hang truc
thanh ky » hanh ky, than ky, thanh tay
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
van hai » van ha, van chat, van phan
va hanh » va thanh, va danh, ban hanh
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet

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

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