Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
dang mat » dang vat, dang mau, dung mat
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 ty » sach y, sach tu, sach thu
dang ma » dang mau, dang mam, tang ma
va cham » va chat, va tham
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 ty ((dang ma) or (dang mat)) hoi. lieu va cham thuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((dang ma) OR (dang mat)) hoi. lieu va cham thuc van hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((dang ma) or (dang mat)) hoi. lieu va cham thuc van hanh ki su triet*.