Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh tai, hanh van
tang mai » tang ma, tang tai, lang mai
hanh va » hang va, hanh vi
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
sach ky » sac ky, sach ty, sach kem
mai hoi » mai khoi, dai hoi, lai hoi
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) OR (sach y)) tang mai hoi. hieu van cam duc va ((hanh vai) or (hanh va)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) tang mai hoi. hieu van cam duc va ((hanh vai) OR (hanh va)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach y)) tang mai hoi. hieu van cam duc va ((hanh vai) or (hanh va)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach y)) tang mai hoi. hieu van cam duc va ((hanh vai) or (hanh va)) cuu tre*.