Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
va thanh » ban thanh, va tinh, le thanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nam xuc » cam xuc, nam xua, nam duoc
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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 ky nang x hoi. hieu van ((nam xuc) or (nam thuc)) ((va thanh) OR (gia thanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu van ((nam xuc) OR (nam thuc)) ((va thanh) OR (gia thanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu van ((nam xuc) or (nam thuc)) ((va thanh) OR (gia thanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu van ((nam xuc) or (nam thuc)) ((va thanh) OR (gia thanh)) di cua tre*.