Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
va trinh » van trinh, va tinh, qua trinh
sang ky » sang kyo, dang ky, tang ky
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
cau loc » hau loc, cau hoc, cau luc
ve cau » ke cau, ve cac, le cau
ban ky » van ky, dan ky
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((ban ky) or (sang ky)) tang xa hoi. hieu va cau loc ((va trinh) OR (lap trinh)) ve cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((ban ky) OR (sang ky)) tang xa hoi. hieu va cau loc ((va trinh) OR (lap trinh)) ve cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((ban ky) or (sang ky)) tang xa hoi. hieu va cau loc ((va trinh) OR (lap trinh)) ve cau tren".
• Adding a wildcard symbol may retrieve word variants: te ((ban ky) or (sang ky)) tang xa hoi. hieu va cau loc ((va trinh) OR (lap trinh)) ve cau tren*.