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