Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
cham thuc » pham thuc, tham thuc, pham thuoc
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
hanh dau » hang dau, danh dau, han dau
toc sach » hoc sach, doc sach, thuoc sach
tang ma » mang may, tang van
va hanh » van hanh, va thanh, va danh
y tang » ky tang, 6 tang, 7 tang
dau su » dau tu, dan su, da su

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) OR (toc sach)) y tang ma hoa. hieu van ((cham thuc) or (nham thuc)) va hanh dau su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y tang ma hoa. hieu van ((cham thuc) OR (nham thuc)) va hanh dau su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) y tang ma hoa. hieu van ((cham thuc) or (nham thuc)) va hanh dau su triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) y tang ma hoa. hieu van ((cham thuc) or (nham thuc)) va hanh dau su triet*.