Perhaps you should try some spelling variations:
kien chao » vien cao, dien cho, khien cho
dieu kien » dieu khien, dien bien
hanh tai » thanh tai, hang tai, han tai
hanh vai » hanh vi, hanh va, hanh van
cac khoi » cac thoi, cac khoan, cach thoi
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
xu va » xu van, tu va, su va
me va » te va, ke va, le va
ky va » ly va, ke va, my va

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 va) or (me va)) cac khoi. dieu kien chao xu va ((hanh vai) OR (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky va) OR (me va)) cac khoi. dieu kien chao xu va ((hanh vai) OR (hanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ((ky va) or (me va)) cac khoi. dieu kien chao xu va ((hanh vai) OR (hanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ((ky va) or (me va)) cac khoi. dieu kien chao xu va ((hanh vai) OR (hanh tai)) cua tre*.