Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
dang mau » dong mau, dang van, dang su
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
vu dang » su dang, vu quang, cua dang
mau hoi » cau hoi, mai hoi, mau ho
hanh ki » hanh vi, hanh ky, hanh kien
ki su » ky su

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 vu dang mau hoi. ((lieu va) or (hieu qua)) tham thuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu dang mau hoi. ((lieu va) OR (hieu qua)) tham thuc van hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach vu dang mau hoi. ((lieu va) or (hieu qua)) tham thuc van hanh ki su triet*.