Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
vu sach » vu bach, su sach
thi cuu » thi cuc, thi huu, thi cu
dau thi » cau thi, dan thi, dao thi
cac xuc » cam xuc, cac nuoc, chat xuc
nang ma » tang ma, sang ma, nang cao
cuu tre » cua tre, cau tren, cau treo
nang xa » nang x, lang xa, mang xa
xuc va » duc va, tuc va, luc va
va dau » va dao

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 ((nang xa) or (nang ma)) hoi. lieu va cac xuc va dau thi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky ((nang xa) OR (nang ma)) hoi. lieu va cac xuc va dau thi cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu khach)) ky ((nang xa) or (nang ma)) hoi. lieu va cac xuc va dau thi cuu tre*".