Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
day manh » van manh, duc manh, ha manh
day danh » dai danh, dao danh, day dan
nam thuc » nam thuoc, am thuc, nam thu
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ca tren » cau tren, cu tren, la tren
va nam » van nam, ha nam, va nay
vai ca » vai cac, vai cua, bai ca

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 y ((nang ma) or (nang x)) hoi. hieu va nam thuc ((day danh) OR (day manh)) vai ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang ma) OR (nang x)) hoi. hieu va nam thuc ((day danh) OR (day manh)) vai ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y ((nang ma) or (nang x)) hoi. hieu va nam thuc ((day danh) OR (day manh)) vai ca tren".
• Adding a wildcard symbol may retrieve word variants: thu sach y ((nang ma) or (nang x)) hoi. hieu va nam thuc ((day danh) OR (day manh)) vai ca tren*.