Perhaps you should try some spelling variations:
doan dinh » doan hinh, doan tinh, doan minh
hoc sach » hoc sinh, hoc cac, hoc anh
dinh cuu » dinh chi
doc sach » toc sach, nuoc sach, dac sac
va doan » va doanh, van doan, va dan
va cham » va chat, va tham
cuu tre » cua tre, cau tren, cau treo
nang ro » nang co, nang ho, nang ra
ro hoc » co hoc, mo hoc, o hoc
luc va » duc va, tuc va, loc va
v nang » va nang, vu nang, van nang
va cam » va cac, va cao, va cai

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 ro hoc. hieu ((va cam) OR (va cham)) luc 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 ro hoc. hieu ((va cam) OR (va cham)) luc va doan dinh cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (doc sach)) v nang ro hoc. hieu ((va cam) OR (va cham)) luc va doan dinh cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (doc sach)) v nang ro hoc. hieu ((va cam) OR (va cham)) luc va doan dinh cuu tre*.