Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van hanh » van thanh, ban hanh, van anh
van hoi » van hoc, van hoe, van loi
ve cham » va cham, ve chat, vu cham
tuc van » thuc van, truc van, tuc va
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
ve cam » ve cac, va cam, ve cai
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach y lang ((van hoi) or (van hoa)). hieu ((ve cam) or (ve cham)) tuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach y lang ((van hoi) OR (van hoa)). hieu ((ve cam) OR (ve cham)) tuc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: doc sach y lang ((van hoi) or (van hoa)). hieu ((ve cam) or (ve cham)) tuc van hanh vi cua tre*.