Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
danh dai » danh dau, danh di, vanh dai
danh sai » dung sai, danh bat, danh dau
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
cua te » cua tu
sinh » dinh, minh, kinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sinh ly ((nang xa) or (nang x)) hoi. hieu ve cac thuc vat ((danh dai) OR (danh sai)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sinh ly ((nang xa) OR (nang x)) hoi. hieu ve cac thuc vat ((danh dai) OR (danh sai)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sinh ly ((nang xa) or (nang x)) hoi. hieu ve cac thuc vat ((danh dai) OR (danh sai)) cua te".
• Adding a wildcard symbol may retrieve word variants: hoc sinh ly ((nang xa) or (nang x)) hoi. hieu ve cac thuc vat ((danh dai) OR (danh sai)) cua te*.