Perhaps you should try some spelling variations:
dung doi » huong doi, dung tai, dung mo
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
dung co » dung cho, dung cong, dung cua
cua tre » cua te, cuu tre, cua triet
cam tu » cam thu, nam tu, dam tu

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 ky nang xa hoi. ((hieu ve) or (lieu va)) cam tu va ((dung doi) OR (dung co)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. ((hieu ve) OR (lieu va)) cam tu va ((dung doi) OR (dung co)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. ((hieu ve) or (lieu va)) cam tu va ((dung doi) OR (dung co)) cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. ((hieu ve) or (lieu va)) cam tu va ((dung doi) OR (dung co)) cua tre*.