Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam truc » cau truc, nam truc, lam truoc
hanh tai » thanh tai, hang tai, han tai
dang mau » dong mau, dang van, dang su
van tai » von tai, van tuan
truc va » thuc va, thuc vat, trung va
van cam » van nam, van lam, van cau
sach ky » sach y, sach ty, sach kem
mau hoi » cau hoi, mai hoi, mau ho
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) dang mau hoi. hieu van cam truc va ((hanh tai) OR (van tai)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) dang mau hoi. hieu van cam truc va ((hanh tai) or (van tai)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) dang mau hoi. hieu van cam truc va ((hanh tai) or (van tai)) cua tre*.