Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thu sach » tu sach, thuat sach, thuoc sach
day kinh » ngay kinh, va kinh, ly kinh
thuc day » thuc dan, thuc vat
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
sach ky » sac ky, sach y, sach ty
dai moi » doi moi
dai hoi » dai hoc, dai hai
ky dang » ky nang, ky danh

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 ((dai hoi) OR (dai moi)). hieu ve tham thuc day kinh ((vai cua) or (hai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky dang ((dai hoi) OR (dai moi)). hieu ve tham thuc day kinh ((vai cua) OR (hai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky dang ((dai hoi) OR (dai moi)). hieu ve tham thuc day kinh ((vai cua) or (hai cua)) te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky dang ((dai hoi) OR (dai moi)). hieu ve tham thuc day kinh ((vai cua) or (hai cua)) te*.