Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
dua tren » dung tren
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
dang xa » dang xay, dang ha, dang va
lang xa » lang ha, dang xay, lang van
va pham » van pham, va phat, va phap
duc van » duc va, duc tan, duc manh
su sai » su tai, su hai, su dai
sai ky » sac ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky ((dang xa) OR (lang xa)) hoi. hieu va pham duc van hanh thai ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky ((dang xa) OR (lang xa)) hoi. hieu va pham duc van hanh thai ((dua tren) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky ((dang xa) OR (lang xa)) hoi. hieu va pham duc van hanh thai ((dua tren) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: su sai ky ((dang xa) OR (lang xa)) hoi. hieu va pham duc van hanh thai ((dua tren) or (cua te))*.