Perhaps you should try some spelling variations:
dang khai » dang khoi, dang hai, quang khai
khai cua » thai cua, hai cua, khi cua
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu van » hieu va, thien van, lieu va
va dang » van dang, va nang, va lang
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
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: thuat ((((sach ty) OR (sach tu))) or (sac ky)) nang xa hoi. hieu van cac 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 cac nuoc va dang khai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((((sach ty) OR (sach tu))) or (sac ky)) nang xa hoi. hieu van cac 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 cac nuoc va dang khai cua te*.