Perhaps you should try some spelling variations:
co sach » bo sach, cuon sach, hoc 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: co sach y ((nang ma) or (sang ma)) hoi. hieu le dat nuoc va hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co 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: co sach y ((nang ma) or (sang ma)) hoi. hieu le dat nuoc va hanh vi cuu tre*.