Perhaps you should try some spelling variations:
van khanh » van thanh, van hanh, van anh
thai cuu » thai cua, thi cuc, thai xu
nuoc van » nuoc va, nuoc san, luoc van
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu ve » hieu va, hieu van
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
tu sac » tu sach, tu cac, tu san
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: tu sac ky nang ((o hoi) or (o hai)). hieu ve cac nuoc van khanh ((thai cuu) or (tai cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((o hoi) OR (o hai)). hieu ve cac nuoc van khanh ((thai cuu) OR (tai cuc)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((o hoi) or (o hai)). hieu ve cac nuoc van khanh ((thai cuu) or (tai cuc)) tre*.