Perhaps you should try some spelling variations:
dang khai » dang khoi, dang hai, quang khai
hieu van » hieu va, thien van, lieu va
khai cua » thai cua, hai cua, khi cua
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
nang xa » nang x, lang xa, nang ma
van dat » van dao, van dau, dan dat
va dang » van dang, va nang, va lang
sac ky » cac ky, sai ky
cua te » cua tu
nuoc » quoc, duoc, ngoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((((sach ty) or (sach tu))) or (sac ky)) nang xa hoi. hieu van dat nuoc va dang khai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((((sach ty) OR (sach tu))) OR (sac ky)) nang xa hoi. hieu van dat nuoc va dang khai cua te.
• Adding a wildcard symbol may retrieve word variants: thuat ((((sach ty) or (sach tu))) or (sac ky)) nang xa hoi. hieu van dat nuoc va dang khai cua te*.