Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, co sach
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hieu le » hieu ve, hieu he, hieu ly
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
le dat » le dan, de dat, le dac
vi cuu » vi luu, vinh cuu
nuoc » quoc, duoc, ngoc

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 ((nang ma) OR (sang ma)) hoi. hieu le dat nuoc va hanh vi cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((nang ma) OR (sang ma)) hoi. hieu le dat nuoc va hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang ma) OR (sang ma)) hoi. hieu le dat nuoc va hanh vi cuu tre*.