Perhaps you should try some spelling variations:
danh thanh » dinh thanh, dang thanh, nhanh thanh
xanh hanh » ban hanh, van hanh, dang hanh
su sach » so sach
qua cam » qua cham, qua cac, qua ca
cam thu » nam thu, cac thu, ca thu
vu sach » vu bach, vu khach
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
y nang » ky nang, ly nang, v nang
de cua » le cua, te cua, dieu cua
o hoc » co hoc, mo hoc, so hoc

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) or (vu sach)) y nang o hoc. hieu qua cam thu ((xanh hanh) or (danh thanh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) y nang o hoc. hieu qua cam thu ((xanh hanh) OR (danh thanh)) de cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) y nang o hoc. hieu qua cam thu ((xanh hanh) or (danh thanh)) de cua tre*.