Perhaps you should try some spelling variations:
cham thuc » pham thuc, tham thuc, pham thuoc
nham thuc » nhan thuc, nam thuc, nham thu
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
hanh dau » hang dau, danh dau, han dau
te sach » toc sach
tang ma » mang may, tang van
dau cua » dai cua, day cua, cau cua
sach v » sach va, sach y, sach 2
v tang » 6 tang, 7 tang, 5 tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach v tang ma hoa. hieu van ((cham thuc) or (nham thuc)) van hanh dau cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v tang ma hoa. hieu van ((cham thuc) OR (nham thuc)) van hanh dau cua triet.
• Adding a wildcard symbol may retrieve word variants: te sach v tang ma hoa. hieu van ((cham thuc) or (nham thuc)) van hanh dau cua triet*.