Perhaps you should try some spelling variations:
sang tay » sang tao, sang tai, sang tac
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
tay hoi » tay ho, tao hoi, tay thai
va hanh » van hanh, va thanh, va danh
le dat » de dat, le dac, ve dat
le dan » ke dan
vi cau » va cau, ve cau, di cau

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 _ sang tay hoi. hieu ((le dat) or (le dan)) nuoc va hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach _ sang tay hoi. hieu ((le dat) OR (le dan)) nuoc va hanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: so sach _ sang tay hoi. hieu ((le dat) or (le dan)) nuoc va hanh vi cau tren*.