Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
y sang » _ sang, duy sang
le dat » de dat, le dac, ve dat
le dan » ke dan
ma hoi » xa hoi, ma hoa, me hoi
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 y sang ((ma hoi) OR (mai hoi)). hieu ((le dat) or (le dan)) nuoc va hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y sang ((ma hoi) OR (mai hoi)). hieu ((le dat) OR (le dan)) nuoc va hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y sang ((ma hoi) OR (mai hoi)). hieu ((le dat) or (le dan)) nuoc va hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: so sach y sang ((ma hoi) OR (mai hoi)). hieu ((le dat) or (le dan)) nuoc va hanh vi cuu tre*.