Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, lieu vien
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
vien va » dien va, vien da, tien va
cua tre » cua te, cuu tre, cua triet
xang o » lang o, tang o, dang o
vi cua » vai cua, di cua
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty xang o hoi. hieu vien va thuc van hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: su sach ty xang o hoi. hieu vien va thuc van hanh vi cua tre*.