Perhaps you should try some spelling variations:
oai xanh » oai thanh, loai danh, mai anh
quoc oai » quoc hoi
cua tre » cua te, cuu tre, cua triet
ve phan » va phan, ke phan, ve phat
ky dang » ky nang, ky danh
xanh di » danh di, vanh dai, xanh tai
di cua » dai cua, doi cua, de cua
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ma hoi » mai hoi, ma hoa, me hoi
ve han » ve hanh, ve ban, va han

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 dang ((ma hoi) OR (xa hoi)). hieu ((ve han) or (ve phan)) quoc oai xanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky dang ((ma hoi) OR (xa hoi)). hieu ((ve han) OR (ve phan)) quoc oai xanh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky dang ((ma hoi) OR (xa hoi)). hieu ((ve han) or (ve phan)) quoc oai xanh di cua tre*".