Perhaps you should try some spelling variations:
khanh thai » nhanh thai, khanh thanh, khanh thuan
van khanh » van thanh, van hanh, van anh
dua tren » dung tren
thai dua » thai cua, thi dua, thai doan
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu van » hieu va, thien van, lieu va
cac xuc » cam xuc, chat xuc, cac cuoc
thu sac » thu sach, thu san, thu xac
sac ky » cac ky, sai ky
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky nang ((o hoi) or (o hai)). hieu van ((cac xuc) or (cac nuoc)) van khanh thai dua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang ((o hoi) OR (o hai)). hieu van ((cac xuc) OR (cac nuoc)) van khanh thai dua tren.
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang ((o hoi) or (o hai)). hieu van ((cac xuc) or (cac nuoc)) van khanh thai dua tren*.