Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
thu nang » thi nang, thu hang, thu bang
hanh hai » thanh hai, nhanh hai, hang hai
vat hanh » vat thanh, van hanh, va hanh
so sach » bo sach, co sach, hoc sach
hai cua » thai cua, dai cua, hoi cua
so sanh » do sanh
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
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: ((so sach) or (so sanh)) thu nang ((mai hoi) or (dai hoi)). hieu ve pham thuc vat hanh hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) thu nang ((mai hoi) OR (dai hoi)). hieu ve pham thuc vat hanh hai cua te.
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) thu nang ((mai hoi) or (dai hoi)). hieu ve pham thuc vat hanh hai cua te*.