Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cham thuc » nham thuc, pham thuc, pham thuoc
dang xay » dang van, van xay
vat hanh » vat thanh, van hanh, va hanh
te sach » toc sach
lang xa » lang ha, lang van
hieu ve » hieu va, hieu van
cua tuc » cua duc, cua tu, cua thuoc
vi cua » vai cua, di cua

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 y ((lang xa) or (dang xay)) hoi. hieu ve ((cham thuc) OR (tham thuc)) vat hanh vi cua tuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((lang xa) OR (dang xay)) hoi. hieu ve ((cham thuc) OR (tham thuc)) vat hanh vi cua tuc*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((lang xa) or (dang xay)) hoi. hieu ve ((cham thuc) OR (tham thuc)) vat hanh vi cua tuc*".