Perhaps you should try some spelling variations:
hanh hoi » hanh thoi, hanh noi, hanh hoa
van hanh » van thanh, ban hanh, van anh
quoc van » quoc va, quoc ban, quoc lan
dang xay » dang van, van xay
cac quoc » cac nuoc, cac cuoc, cao quoc
te sach » toc sach
qua cac » cua cac
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, lang van
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty ((lang xa) or (dang xay)) hoi. hieu qua cac quoc van hanh hoi ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((lang xa) OR (dang xay)) hoi. hieu qua cac quoc van hanh hoi ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((lang xa) or (dang xay)) hoi. hieu qua cac quoc van hanh hoi ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((lang xa) or (dang xay)) hoi. hieu qua cac quoc van hanh hoi ((cua te) OR (cua tu))*.