Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
sach tu » sach thu, cach tu, sach ty
van cac » van hac, van cau, van bac
cuu tre » cua tre, cau tren, cau treo
tu ang » tu lang, tu anc, tu anh
ang xa » lang xa, mang xa, dang xay
xac va » tac va, ac va, bac va
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tu ang xa hoi. hieu van cac ((xac va) OR (duc va)) hanh vi cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach tu ang xa hoi. hieu van cac ((xac va) OR (duc va)) hanh vi cuu tre*".