Perhaps you should try some spelling variations:
thanh thai » thanh hai, nhanh thai, thanh thao
thanh tai » thanh hai, thanh toan, doanh tai
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ha xuc » hoa xuc, ha duc, chat xuc
van ha » van hoa, van chat, van hanh
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 ha xuc van ((thanh thai) or (thanh tai)) cau 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 ha xuc van ((thanh thai) OR (thanh tai)) cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (o hai)). hieu van ha xuc van ((thanh thai) or (thanh tai)) cau tren*.