Perhaps you should try some spelling variations:
danh dai » danh dau, danh di, danh sai
thuc dan » hoc dan, thuc vat
te sach » toc sach
va cham » va chat, va tham
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
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: te sach ky ((nang ma) OR (sang ma)) hoi. hieu va cham ((thuc dan) or (thuc hanh)) danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang ma) OR (sang ma)) hoi. hieu va cham ((thuc dan) OR (thuc hanh)) danh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang ma) OR (sang ma)) hoi. hieu va cham ((thuc dan) or (thuc hanh)) danh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang ma) OR (sang ma)) hoi. hieu va cham ((thuc dan) or (thuc hanh)) danh dai cua tre*.