Perhaps you should try some spelling variations:
van nhanh » van thanh, van hanh, van khanh
nhanh tri » nhanh thi, thanh tri, nhanh thai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
ro hai » co hai, so hai, do hai
ve cac » va cac, vien cac
o hai » co hai, so hai, o lai

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 ((ro hai) OR (o hai)). hieu ve cac duc van nhanh tri cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((ro hai) OR (o hai)). hieu ve cac duc van nhanh tri cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ro hai) OR (o hai)). hieu ve cac duc van nhanh tri cua tre*.