Perhaps you should try some spelling variations:
nhanh thang » nhanh thanh, nhanh quang, hanh trang
nhanh thai » nhanh thi, nhanh thanh, nhan tai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
xuc van » duc van, luc van, vuc van
van cac » van hac, van cau, van bac
cac xuc » cam xuc, cac nuoc, chat xuc
sach ky » sac ky, sach y, sach ty
ca tren » cau tren, cu tren, la tren
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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 ky nang ((o hoi) or (o hai)). hieu van cac xuc van ((nhanh thai) OR (nhanh thang)) ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoi) OR (o hai)). hieu van cac xuc van ((nhanh thai) OR (nhanh thang)) ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hoi) or (o hai)). hieu van cac xuc van ((nhanh thai) OR (nhanh thang)) ca tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (o hai)). hieu van cac xuc van ((nhanh thai) OR (nhanh thang)) ca tren*.