Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
tu sach » thu sach, su sach, te sach
sach lo » sach dao, sach doi, sach hoi
lo nang » ho nang, ly nang, loai nang
va hanh » van hanh, va thanh, va danh
di cua » doi cua, de cua, do cua
x hoi » xa hoi, o hoi, x ho

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 lo nang x hoi. hieu van nam thuc ((va hanh) or (ban thanh)) ((di cua) OR (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach lo nang x hoi. hieu van nam thuc ((va hanh) OR (ban thanh)) ((di cua) OR (dai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach lo nang x hoi. hieu van nam thuc ((va hanh) or (ban thanh)) ((di cua) OR (dai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach lo nang x hoi. hieu van nam thuc ((va hanh) or (ban thanh)) ((di cua) OR (dai cua)) triet*.