Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
danh dai » danh dau, danh di, danh sai
sach ky » sac ky, sach ty, sach kem
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sach y)) van xay hoi. hieu va tham thuc va danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) van xay hoi. hieu va tham thuc va danh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) van xay hoi. hieu va tham thuc va danh dai cua tre*.