Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sach y, sach ty, sach kem
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
cua su » qua su

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

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