Perhaps you should try some spelling variations:
so sach » bo sach, co sach, hoc sach
nang ma » tang ma, sang ma, nang cao
va hanh » van hanh, va thanh, va danh
so sanh » do sanh
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
le dat » de dat, le dac, ve dat
le dan » ke dan
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) OR (so sanh)) y nang ma 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) OR (so sanh)) y nang ma 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) OR (so sanh)) y nang ma hoi. hieu ((le dat) or (le dan)) nuoc va hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (so sanh)) y nang ma hoi. hieu ((le dat) or (le dan)) nuoc va hanh vi cuu tre*.