Perhaps you should try some spelling variations:
thien van » thi van
thuc dant » thuoc dang, thuc hanh, thuc vat
thuc dan » thuc hanh, hoc dan, thuc vat
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((nang ma) OR (sang ma)) hoi. thien van nam ((thuc dan) or (thuc dant)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((nang ma) OR (sang ma)) hoi. thien van nam ((thuc dan) OR (thuc dant)) hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky ((nang ma) OR (sang ma)) hoi. thien van nam ((thuc dan) or (thuc dant)) hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((nang ma) OR (sang ma)) hoi. thien van nam ((thuc dan) or (thuc dant)) hanh di cua tre*.