Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di 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 y nang xa hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cau duc va danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) cau duc va danh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cau duc va danh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cau duc va danh vi cua tre*.