Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
dung ha » dung va, dung he, dung khoa
sach ty » sach y, sach tu, sach thu
dang xa » dang xay, lang xa, dang ha
tu sach » thu sach, su sach, te sach
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((dang xa) or (dung ha)) hoi. hieu van nam thuc van thanh ((vi cua) or (di cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((dang xa) OR (dung ha)) hoi. hieu van nam thuc van thanh ((vi cua) OR (di cua)) triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((dang xa) or (dung ha)) hoi. hieu van nam thuc van thanh ((vi cua) or (di cua)) triet*.