Perhaps you should try some spelling variations:
khanh thanh » nhanh thanh, thanh thanh, phan thanh
thanh cau » thanh chau, thanh mau, nhanh cau
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach y, sach ty
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
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: thu sach ky nang ((o hoi) or (o hai)). hieu ve cac ((xuc van) or (duc van)) khanh thanh cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((o hoi) OR (o hai)). hieu ve cac ((xuc van) OR (duc van)) khanh thanh cau tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((o hoi) or (o hai)). hieu ve cac ((xuc van) or (duc van)) khanh thanh cau tren*.