Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, nam duoc
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: ((tu sach) or (thu hoach)) ky nang xa hoi. hieu va ((cam duc) OR (pham duc)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) ky nang xa hoi. hieu va ((cam duc) OR (pham duc)) va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu hoach)) ky nang xa hoi. hieu va ((cam duc) OR (pham duc)) va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ky nang xa hoi. hieu va ((cam duc) OR (pham duc)) va hanh vai cua tre*.