Perhaps you should try some spelling variations:
cac thoi » cac toi, cac hop, cac tro
vu khach » vu khanh, vu khac, vay khach
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
cac dac » cac dan, cac dai, cac bac
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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) OR (vu khach)) ky tang xa hoi. hieu van ((cac dac) or (cac thoi)) va tinh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky tang xa hoi. hieu van ((cac dac) OR (cac thoi)) va tinh vi cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu khach)) ky tang xa hoi. hieu van ((cac dac) or (cac thoi)) va tinh vi cuu tre*".