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