Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
hieu van » hieu va, thien van, lieu va
va danh » va dinh, va hanh, dia danh
cac luc » cau luc, coc luc, cac nuoc
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu khach) or (so sach)) ky nang xa hoi. hieu van cac luc ((va danh) OR (va dan)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (so sach)) ky nang xa hoi. hieu van cac luc ((va danh) OR (va dan)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu khach) or (so sach)) ky nang xa hoi. hieu van cac luc ((va danh) OR (va dan)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu khach) or (so sach)) ky nang xa hoi. hieu van cac luc ((va danh) OR (va dan)) dai cua tre*.