Perhaps you should try some spelling variations:
doan dinh » doan hinh, doan tinh, doan minh
hoc sach » hoc sinh, hoc cac, hoc anh
doc sach » toc sach, nuoc sach, dac sac
dinh cuu » dinh chi
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va doan » va doanh, van doan, va dan
cuu tre » cua tre, cau tren, cau treo
v nang » va nang, vu nang, van nang
nang o » nang co, nang ho, nang ro
va cam » va cham, va cac, va cao
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: ((hoc sach) or (doc sach)) v nang o hoc. hieu va cam duc va doan dinh cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (doc sach)) v nang o hoc. hieu va cam duc va doan dinh cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (doc sach)) v nang o hoc. hieu va cam duc va doan dinh cuu tre*.