Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
dang mai » dang hai, dang mau, dang bai
sach ky » sac ky, sach y, sach ty
luc van » luoc van, luu van, duc van
mai hoi » mai khoi, dai hoi, lai hoi
ky dang » ky nang, ky danh
ve cac » va cac, vien cac
ve cau » ke cau, va cau, le cau
vai la » vai va
tai la » tai lam, tai lap, tai ba

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 dang mai hoi. hieu ((ve cau) or (ve cac)) luc van thanh ((vai la) OR (tai la)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky dang mai hoi. hieu ((ve cau) OR (ve cac)) luc van thanh ((vai la) OR (tai la)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky dang mai hoi. hieu ((ve cau) or (ve cac)) luc van thanh ((vai la) OR (tai la)) tren".
• Adding a wildcard symbol may retrieve word variants: thu sach ky dang mai hoi. hieu ((ve cau) or (ve cac)) luc van thanh ((vai la) OR (tai la)) tren*.