Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
vu kham » vu khanh
hoi cua » hoi chuc
hai cua » thai cua, dai cua, lai cua
kham le » pham le
hieu vu » hieu va, hieu ve, hieu su
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
ma hoi » xa hoi, ma hoa, me hoi

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 ky nang ((ma hoi) or (mai hoi)). hieu vu kham le van thanh ((hai cua) OR (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((ma hoi) OR (mai hoi)). hieu vu kham le van thanh ((hai cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((ma hoi) or (mai hoi)). hieu vu kham le van thanh ((hai cua) OR (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((ma hoi) or (mai hoi)). hieu vu kham le van thanh ((hai cua) OR (hoi cua)) tre*.