Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
hang tai » hang va, dung tai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
tai va » thai va, mai va, tri va
thiet » thieu

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 xa hoi. ((hieu van) OR (hieu va)) cham ((xuc va) or (tuc va)) hang tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. ((hieu van) OR (hieu va)) cham ((xuc va) OR (tuc va)) hang tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. ((hieu van) OR (hieu va)) cham ((xuc va) or (tuc va)) hang tai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. ((hieu van) OR (hieu va)) cham ((xuc va) or (tuc va)) hang tai va thiet*.