Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
hai cua » thai cua, dai cua, lai cua
tuc va » thuc va, truc va, tuc xa

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