Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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) OR (hieu qua)) cam duc va hanh va 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) OR (hieu qua)) cam duc va hanh va 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) OR (hieu qua)) cam duc va hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ky nang xa hoi. ((hieu va) OR (hieu qua)) cam duc va hanh va cua tre*.