Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
dang xay » dang van
tai cua » thai cua, tai cuc, tri cua
luc van » luoc van, luu van, duc van
cao luc » bao luc, cao duc, cao suc
sach ky » sach y, sach ty, sach kem
va cao » va cac, va co, va dao
sac ky » cac ky, sai 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 ((sach ky) OR (sac ky)) ((dang xay) or (van xay)) hoi. lieu va cao luc van hanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) ((dang xay) OR (van xay)) hoi. lieu va cao luc van hanh tai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) ((dang xay) or (van xay)) hoi. lieu va cao luc van hanh tai cua te*".