Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
tai khoi » tai khoa, mai khoi, tao khoi
hanh dai » hanh tai, hanh dao, vanh dai
su sach » so sach, vu sach
tai hoi » dai hoi, tai hai, tai hoe
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
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: su sach y nang ((tai hoi) or (tai khoi)). hieu ve pham thuc va hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((tai hoi) OR (tai khoi)). hieu ve pham thuc va hanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((tai hoi) or (tai khoi)). hieu ve pham thuc va hanh dai cua te*.