Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
van cam » van lam, van cau, van dam
sach ky » sach y, sach ty, sach kem
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, luc va
vi cua » vai cua, di cua
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: su ((sach ky) or (sac ky)) nang o hoc. thien ((van cam) OR (van nam)) xuc va thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang o hoc. thien ((van cam) OR (van nam)) xuc va thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sac ky)) nang o hoc. thien ((van cam) OR (van nam)) xuc va thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) nang o hoc. thien ((van cam) OR (van nam)) xuc va thanh vi cua tre*.