Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thu sach » tu sach, thuat sach, thuoc sach
tu trang » thu trang, tu trong, ta trang
doanh va » doan va, doanh tai, doanh cua
danh vai » danh sai, danh va, doanh van
ve tham » va tham, ve cham, vi tham
sach tu » sach thu, cach tu, sach ty
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
va hoi » va hoc, va hoa

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 tu trang ((va hoi) OR (xa hoi)). hieu ve tham thuc vat ((danh vai) or (doanh va)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach tu trang ((va hoi) OR (xa hoi)). hieu ve tham thuc vat ((danh vai) OR (doanh va)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach tu trang ((va hoi) OR (xa hoi)). hieu ve tham thuc vat ((danh vai) or (doanh va)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: thu sach tu trang ((va hoi) OR (xa hoi)). hieu ve tham thuc vat ((danh vai) or (doanh va)) cuu tre*.