Perhaps you should try some spelling variations:
bieu hien » dieu hien, dieu khien, bien phien
hieu viec » nhieu viec, hieu ve, sieu viet
sach duoc » sach nuoc, sach dao, sach dung
hang hoa » hang khoa, thanh hoa, hang va
duoc gia » duoc giao, quoc gia, duc gia
gia hanh » gia thanh, giao hanh, gia anh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
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: su sach ty hang hoa hoc. ((hieu viec) or (bieu hien)) sach duoc gia hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty hang hoa hoc. ((hieu viec) OR (bieu hien)) sach duoc gia hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty hang hoa hoc. ((hieu viec) or (bieu hien)) sach duoc gia hanh vi cua tre*.