Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thanh do » thanh de, thanh pho, thanh hoa
lieu van » lieu va, hieu van, sieu van
va triet » va thiet, va trien, ve triet
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
tuc va » truc va, tuc xa, duc va
do va » do van, so va

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 ky ((nang xa) or (nang x)) hoi. lieu van nam ((tuc va) OR (thuc va)) thanh do va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky ((nang xa) OR (nang x)) hoi. lieu van nam ((tuc va) OR (thuc va)) thanh do va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky ((nang xa) or (nang x)) hoi. lieu van nam ((tuc va) OR (thuc va)) thanh do va triet".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky ((nang xa) or (nang x)) hoi. lieu van nam ((tuc va) OR (thuc va)) thanh do va triet*.