Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cham thuc » nham thuc, pham thuc, pham thuoc
thu sach » tu sach, thuat sach, thuoc sach
day hanh » day nhanh, day thanh, dao hanh
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
hanh di » hanh vi, hanh de, hang di
di cua » dai cua, doi cua, de cua
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 nang cao hoi. hieu ve ((cham thuc) OR (tham thuc)) day hanh di cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang cao hoi. hieu ve ((cham thuc) OR (tham thuc)) day hanh di cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang cao hoi. hieu ve ((cham thuc) OR (tham thuc)) day hanh di cua te*.