Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
danh du » danh dau, danh tu, dinh du
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cuu tre » cua tre, cau tren, cau treo
sach v » sach va, sach y, sach 2
luc va » tuc va, loc va
du cuu » tu cuu

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 v ((nang xa) or (nang ma)) hoi. hieu va tham ((luc va) OR (duc va)) danh du cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v ((nang xa) OR (nang ma)) hoi. hieu va tham ((luc va) OR (duc va)) danh du cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v ((nang xa) or (nang ma)) hoi. hieu va tham ((luc va) OR (duc va)) danh du cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach v ((nang xa) or (nang ma)) hoi. hieu va tham ((luc va) OR (duc va)) danh du cuu tre*.