Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
y dang » ky dang, 2 dang, b dang
_ dang » _ dan, 2 dang, _ danh
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
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 ((y dang) OR (_ dang)) xa hoi. hieu van cam ((xuc va) or (tuc va)) thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y dang) OR (_ dang)) xa hoi. hieu van cam ((xuc va) OR (tuc va)) thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y dang) OR (_ dang)) xa hoi. hieu van cam ((xuc va) or (tuc va)) thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((y dang) OR (_ dang)) xa hoi. hieu van cam ((xuc va) or (tuc va)) thanh vi cua tre*.