Perhaps you should try some spelling variations:
luc ngan » luc nganh, luc nhan, luat ngan
sach thu » sach thue, sach thieu, sach tham
hang vi » hang va, hang di, khang voi
cau luc » cau truc, cau phuc
hieu ve » hieu va, hieu van
ca tren » cau tren, cu tren, la tren
sach ty » sach y, sach tu, xach tay
ve cau » ke cau, va cau, ve cac
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sach thu)) nang x hoi. hieu ve cau luc ngan ((hang vi) or (hanh vi)) ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang x hoi. hieu ve cau luc ngan ((hang vi) OR (hanh vi)) ca tren.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang x hoi. hieu ve cau luc ngan ((hang vi) or (hanh vi)) ca tren*.