Perhaps you should try some spelling variations:
khanh thuan » khanh thuong, thanh tuan, khan than
thuan cuu » thuan cam, thuat cua, tuan cu
tu sach » thu sach, su sach, te sach
luc van » luoc van, luu van, duc van
xuc van » duc van, vuc van, xuc ban
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
o hai » co hai, so hai, o lai
o hoc » co hoc, mo hoc, so hoc

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 hoc) or (o hai)). hieu ve cac ((xuc van) or (luc van)) khanh thuan cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoc) OR (o hai)). hieu ve cac ((xuc van) OR (luc van)) khanh thuan cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoc) or (o hai)). hieu ve cac ((xuc van) or (luc van)) khanh thuan cuu tre*.