Perhaps you should try some spelling variations:
tang mai » tang ma, tang tai, lang mai
cham duc » pham duc, cham soc, pham duy
hanh lam » thanh lap, hanh kem, dinh lam
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 7 tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y tang mai hoi. hieu vu cham duc va ((hanh lam) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y tang mai hoi. hieu vu cham duc va ((hanh lam) OR (hanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y tang mai hoi. hieu vu cham duc va ((hanh lam) or (hanh va)) cua tre*.