Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hien cac » thien cac, vien cac, hieu cac
van chua » va chua, van chia, van chu
chua tre » chua tri, cua tre, chua trieu
te sach » toc sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
lao va » cao va, bao va, dao va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ky lang) OR (ky tang)) xa hoi. hieu hien cac ((lao va) or (tao va)) dinh van chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky tang)) xa hoi. hieu hien cac ((lao va) OR (tao va)) dinh van chua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) OR (ky tang)) xa hoi. hieu hien cac ((lao va) or (tao va)) dinh van chua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) OR (ky tang)) xa hoi. hieu hien cac ((lao va) or (tao va)) dinh van chua tre*.