Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, cuoc cach, cuon sach
hoc sach » hoc sinh, hoc cac, hoc anh
dan dinh » dang dinh, doan dinh, van dinh
dinh cuu » dinh chi
hieu va » lieu va, hieu qua
cam luc » cam xuc, cau luc
cuu tre » cua tre, cau tren, cau treo
v nang » va nang, vu nang, van nang
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
o hoc » mo hoc, so hoc, y 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 (nuoc sach)) v nang ((o hoc) OR (co hoc)). hieu va cam luc va dan dinh cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (nuoc sach)) v nang ((o hoc) OR (co hoc)). hieu va cam luc va dan dinh cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (nuoc sach)) v nang ((o hoc) OR (co hoc)). hieu va cam luc va dan dinh cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (nuoc sach)) v nang ((o hoc) OR (co hoc)). hieu va cam luc va dan dinh cuu tre*.