Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh voi » hanh noi, hanh moi, lanh voi
sach va » sach xa, sach ha, sach dao
va nang » van nang, da nang, cam nang
nang xa » nang x, lang xa, nang ma
hieu vu » hieu va, hieu ve, hieu su
vu kham » vu khanh
tuc va » thuc va, truc va, duc va

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

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