Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
dang dinh » dang sinh, dang hanh
tang mai » tang ma, tang tai, lang mai
vai cua » dai cua, hai cua, lai cua
ve cham » va cham, ve chat, vu cham
sach ky » sac ky, sach ty, sach kem
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sach y)) tang mai hoi. hieu ve cham thuc ((dang dinh) OR (dang dieu)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach y)) tang mai hoi. hieu ve cham thuc ((dang dinh) OR (dang dieu)) vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sach y)) tang mai hoi. hieu ve cham thuc ((dang dinh) OR (dang dieu)) vai cua te".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sach y)) tang mai hoi. hieu ve cham thuc ((dang dinh) OR (dang dieu)) vai cua te*.