Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
ve thanh » le thanh, de thanh, den thanh
cham cuu » cap cuu, chat cua
van cham » van chat, van tham, va cham
cua tre » cuu tre, cua triet, dua tren
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cuu ve » cuu va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty ((nang xa) OR (nang ma)) hoi. hieu van cham cuu ve thanh hai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (nang ma)) hoi. hieu van cham cuu ve thanh hai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) OR (nang ma)) hoi. hieu van cham cuu ve thanh hai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) OR (nang ma)) hoi. hieu van cham cuu ve thanh hai ((cua tre) or (cua te))*.