Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
qua tham » qua cham, qua than, qua thanh
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach kem, sach hay
sach ty » sach tu, sach thu, xach tay
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
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: hoc ((((sach ky) OR (sach y))) or (sach ty)) nang ma hoi. hieu qua tham thuc van hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((((sach ky) OR (sach y))) OR (sach ty)) nang ma hoi. hieu qua tham thuc van hanh vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((((sach ky) OR (sach y))) or (sach ty)) nang ma hoi. hieu qua tham thuc van hanh vi cua triet".
• Adding a wildcard symbol may retrieve word variants: hoc ((((sach ky) OR (sach y))) or (sach ty)) nang ma hoi. hieu qua tham thuc van hanh vi cua triet*.