Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
nang xa » nang x, lang xa, nang ma
sang ma » tang ma, nang ma, sang tao
hieu va » lieu va, hieu qua
gia duc » giao duc, gia muc, gia thuc
va danh » va dinh, va dan, va hanh
danh du » danh dau, danh tu, dinh du
va gia » va giai
du cau » cu cau, da cau, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach 2) or (sach y)) ((nang xa) or (sang ma)) hoi. hieu va gia duc va danh du cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach 2) OR (sach y)) ((nang xa) OR (sang ma)) hoi. hieu va gia duc va danh du cau tren.
• Adding a wildcard symbol may retrieve word variants: toc ((sach 2) or (sach y)) ((nang xa) or (sang ma)) hoi. hieu va gia duc va danh du cau tren*.