Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
va hang » van hang, va nang, va lang
nam luc » nang luc, nhan luc, nam thuc
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
luc va » duc va, tuc va, loc va
di cu » di cau, di cua, di du
li du » ly du

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 tang) or (ky dang)) xa hoi. hieu van nam luc va hang ((di cu) or (li du)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky tang) OR (ky dang)) xa hoi. hieu van nam luc va hang ((di cu) OR (li du)) tren.
• Adding a wildcard symbol may retrieve word variants: su sach ((ky tang) or (ky dang)) xa hoi. hieu van nam luc va hang ((di cu) or (li du)) tren*.