Perhaps you should try some spelling variations:
luc ngan » luc nganh, luc nhan, luat ngan
sach ty » sach y, sach thu, xach tay
hang vi » hang va, hanh vi, hang di
cau luc » cau truc, cau phuc
hieu va » lieu va, hieu qua
ca tren » cau tren, cu tren, la tren
sach tu » sach thu, cach tu, sach uu
va cau » van cau, va cac, va dau
x hoi » xa hoi, x ho, 5 hoi
vi ca » vit ca, li ca, va ca
o hoi » co hoi, o hoc, o hai

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 tu)) nang ((x hoi) OR (o hoi)). hieu va cau luc ngan hang vi ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) nang ((x hoi) OR (o hoi)). hieu va cau luc ngan hang vi ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach tu)) nang ((x hoi) OR (o hoi)). hieu va cau luc ngan hang vi ca tren".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach tu)) nang ((x hoi) OR (o hoi)). hieu va cau luc ngan hang vi ca tren*.