Perhaps you should try some spelling variations:
khoa tang » kho tang, khoa dang, khoa tieng
cac khoa » cac khoan, cac khoi, dac khoa
cham sao » cham vao, nam sao, cham o
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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 khoa tang ma hoi. hieu ve ((cham sao) OR (cham soc)) ban hanh di ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac khoa tang ma hoi. hieu ve ((cham sao) OR (cham soc)) ban hanh di ((cua tre) OR (cau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac khoa tang ma hoi. hieu ve ((cham sao) OR (cham soc)) ban hanh di ((cua tre) or (cau tren))*".