Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
cam thuc » am thuc, nam thuc, cam thu
va thanh » ban thanh, va tinh, le thanh
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hoa cua » hoa chat, hoa xuat
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang xa hoi. ((hieu van) or (thien van)) cam thuc ((va thanh) OR (gia thanh)) hoa cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. ((hieu van) OR (thien van)) cam thuc ((va thanh) OR (gia thanh)) hoa cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. ((hieu van) or (thien van)) cam thuc ((va thanh) OR (gia thanh)) hoa cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. ((hieu van) or (thien van)) cam thuc ((va thanh) OR (gia thanh)) hoa cua tre*.