Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, doc sach, thuoc sach
thu nang » thi nang, thu hang, thu bang
sach thu » sach thue, sach thieu, sach tham
dinh vi » dinh ve, dinh viet, dinh tri
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach thu nang ((ma hoi) or (ma hoa)). hieu ve pham thuc va ((dinh vi) or (chinh tri)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thu nang ((ma hoi) OR (ma hoa)). hieu ve pham thuc va ((dinh vi) OR (chinh tri)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach thu nang ((ma hoi) or (ma hoa)). hieu ve pham thuc va ((dinh vi) or (chinh tri)) cua tre*.