Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
cam truc » cau truc, nam truc, lam truoc
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
sach v » sach va, sach y, sach 2
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: su sach v ((nang xa) or (((mang may) or (nang cao)))) hoi. hieu van cam truc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v ((nang xa) OR (((mang may) OR (nang cao)))) hoi. hieu van cam truc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach v ((nang xa) or (((mang may) or (nang cao)))) hoi. hieu van cam truc van hanh vi cua tre*.