Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
thanh van » thanh san, thanh toan, thanh phan
toc sach » hoc sach, doc sach, thuoc sach
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
hanh va » hang va, hanh vi
cuu tre » cua tre, cau tren, cau treo

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) or (toc sach)) ly nang x ho. hieu ve cham thuc vat ((thanh van) or (hanh va)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ly nang x ho. hieu ve cham thuc vat ((thanh van) OR (hanh va)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ly nang x ho. hieu ve cham thuc vat ((thanh van) or (hanh va)) cuu tre*.