Perhaps you should try some spelling variations:
chieu ke » hieu ky, hieu ve, hieu kem
ca tren » cau tren, cu tren, la tren
danh li » dan li, dinh li, danh lien
lang xa » lang ha, dang xay, lang van
hieu ke » hieu kem, hieu ky, hieu ve
danh di » danh du, xanh di, danh dien
truc va » thuc va, thuc vat, trung va
sinh y » sinh ly
y lang » o lang, _ lang, tay lang

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 y lang xa hoi. ((hieu ke) OR (chieu ke)) cau truc va ((danh li) or (danh di)) ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sinh y lang xa hoi. ((hieu ke) OR (chieu ke)) cau truc va ((danh li) OR (danh di)) ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sinh y lang xa hoi. ((hieu ke) OR (chieu ke)) cau truc va ((danh li) or (danh di)) ca tren".
• Adding a wildcard symbol may retrieve word variants: hoc sinh y lang xa hoi. ((hieu ke) OR (chieu ke)) cau truc va ((danh li) or (danh di)) ca tren*.