Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
smo hoc » so hoc
van can » van canh, van ban, ban can
can tac » canh tac, cac tac, cong tac
mo hoc » mon hoc, co hoc
cua su » qua su
gia » giao

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang ((mo hoc) or (smo hoc)). hieu van can tac gia ((thanh hai) or (thanh san)) cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ((mo hoc) OR (smo hoc)). hieu van can tac gia ((thanh hai) OR (thanh san)) cua su.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ((mo hoc) or (smo hoc)). hieu van can tac gia ((thanh hai) or (thanh san)) cua su*.