Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang xa hoi. ((((hieu ve) or (hieu va))) or (hieu van)) cac nuoc va danh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. ((((hieu ve) OR (hieu va))) OR (hieu van)) cac nuoc va danh di cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. ((((hieu ve) or (hieu va))) or (hieu van)) cac nuoc va danh di cua tre*.