Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
doc sach » hoc sach, toc sach, nuoc sach
thuc van » thuc vat, thuc dan, thuc va
dong hoa » dong hoc, dong co
te sach » toc sach
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky dong » ly dong, ky dang, ky cong
cua tre » cua te, cuu tre, cua triet
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: ((te sach) or (doc sach)) ky dong hoa hoi. hieu ((va cac) or (ket cau)) thuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ky dong hoa hoi. hieu ((va cac) OR (ket cau)) thuc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ky dong hoa hoi. hieu ((va cac) or (ket cau)) thuc van hanh vi cua tre*.