Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
va cham » va chat, va tham
doi va » hoi va, noi va, dai va
di va » dai va, di vao, di vat

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach ky) OR (sach ty)) nang xa hoi. hieu va cham thuc van hanh ((di va) or (doi va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ky) OR (sach ty)) nang xa hoi. hieu va cham thuc van hanh ((di va) OR (doi va)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ky) OR (sach ty)) nang xa hoi. hieu va cham thuc van hanh ((di va) or (doi va)) triet*".