Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
tu sach » thu sach, su sach, te sach
cam loc » cam lo
hai cuc » tai cuc, hai cua, thai cua
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
mau hoi » cau hoi, mau ho, mau hop
ky dang » ky nang, ky danh
cuc tre » duc tre, cua tre, cuu tre
ve cam » ve cham, ve cac, va cam

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 dang ((mau hoi) or (mai hoi)). hieu ve cam loc ((va thanh) OR (ban thanh)) hai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang ((mau hoi) OR (mai hoi)). hieu ve cam loc ((va thanh) OR (ban thanh)) hai cuc tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang ((mau hoi) or (mai hoi)). hieu ve cam loc ((va thanh) OR (ban thanh)) hai cuc tre*".