Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
vu sach » vu bach, su sach, vu khach
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
x hoi » o hoi, x ho, 5 hoi
vi va » vi van, vai va, vu va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (co sach)) ky nang ((x hoi) or (xa hoi)). hieu ve cam thuc day hanh vi va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (co sach)) ky nang ((x hoi) OR (xa hoi)). hieu ve cam thuc day hanh vi va thiet.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (co sach)) ky nang ((x hoi) or (xa hoi)). hieu ve cam thuc day hanh vi va thiet*.