Perhaps you should try some spelling variations:
tay quang » tac quang, tao quang, vay quang
tai quang » thai quang, mai quang, cai quang
hieu van » hieu va, thien van, lieu va
cap nuoc » dat nuoc
tu sach » thu sach, su sach, te sach
van cap » van cau, van dap, van ca
va tinh » may tinh
tinh vi » trinh vi, tinh voi, tinh va
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((tay quang) or (tai quang)) xa hoi. hieu van cap nuoc va tinh vi ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tay quang) OR (tai quang)) xa hoi. hieu van cap nuoc va tinh vi ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tay quang) or (tai quang)) xa hoi. hieu van cap nuoc va tinh vi ((cua tu) OR (cua su))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tay quang) or (tai quang)) xa hoi. hieu van cap nuoc va tinh vi ((cua tu) OR (cua su))*.