Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
sinh ky » sinh ly, sinh y, kinh ky
cam luc » cam xuc, cau luc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
lang xa » lang ha, lang van
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
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: hoc sinh ky ((lang xa) OR (dang xay)) hoi. ((hieu ve) or (hieu van)) cam luc va dan di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sinh ky ((lang xa) OR (dang xay)) hoi. ((hieu ve) OR (hieu van)) cam luc va dan di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sinh ky ((lang xa) OR (dang xay)) hoi. ((hieu ve) or (hieu van)) cam luc va dan di cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sinh ky ((lang xa) OR (dang xay)) hoi. ((hieu ve) or (hieu van)) cam luc va dan di cua tre*.