Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
nang o » nang co, nang ho, nang ro
ve cac » vien cac
xuc va » duc va, tuc va, luc va
cua te » cua tu
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang o hoi. hieu ((ve cac) or (va cac)) xuc va hanh vi ((cua te) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang o hoi. hieu ((ve cac) OR (va cac)) xuc va hanh vi ((cua te) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hoi. hieu ((ve cac) or (va cac)) xuc va hanh vi ((cua te) or (dau tren))*.