Perhaps you should try some spelling variations:
bat thanh » ban thanh, bac thanh, dat thanh
thanh va » thanh van, hanh va, thanh ha
kho tang » cao tang
chat luc » chat xuc, chat lua, nhan luc
tu sach » thu sach, su sach, te sach
ve chat » va chat, van chat
ky tang » ky nang, ky dang, ky trong
luc bat » suc bat, luc nhat, luat bat
hieu ve » hieu va, hieu van
va cua » va chua, via cua, ca cua
ma hoi » mai hoi, xa hoi, 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: tu sach ((ky tang) OR (kho tang)) ((ma hoi) or (ma hoa)). hieu ve chat luc bat thanh va cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (kho tang)) ((ma hoi) OR (ma hoa)). hieu ve chat luc bat thanh va cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky tang) OR (kho tang)) ((ma hoi) or (ma hoa)). hieu ve chat luc bat thanh va cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) OR (kho tang)) ((ma hoi) or (ma hoa)). hieu ve chat luc bat thanh va cua vat*.