Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
hanh vai » hanh vi, hanh va, hanh tai
vu sach » vu bach, su sach
hieu va » lieu va, hieu qua
cam tuc » cam tu, nam thuc, dam thuc
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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 x ho. hieu va ((cam tuc) OR (cam xuc)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky nang x ho. hieu va ((cam tuc) OR (cam xuc)) va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (vu khach)) ky nang x ho. hieu va ((cam tuc) OR (cam xuc)) va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khach)) ky nang x ho. hieu va ((cam tuc) OR (cam xuc)) va hanh vai cua tre*.