Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cham thuc » nham thuc, pham thuc, pham thuoc
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
cuu tre » cua tre, cau tren, cau treo
di cuu » di cau, di cua, dinh cuu

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 ty xang xa hoi. hieu va ((cham thuc) OR (tham thuc)) ((va danh) or (van hanh)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty xang xa hoi. hieu va ((cham thuc) OR (tham thuc)) ((va danh) OR (van hanh)) di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty xang xa hoi. hieu va ((cham thuc) OR (tham thuc)) ((va danh) or (van hanh)) di cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty xang xa hoi. hieu va ((cham thuc) OR (tham thuc)) ((va danh) or (van hanh)) di cuu tre*.