Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
ty nang » ky nang, ty xang, ty hang
van bac » van ban, van bao, van hac
cua tre » cua te, cuu tre, dua tren
bo van » vo van, so van, do van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ty nang x ho. hieu van bac bo van thanh vi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang x ho. hieu van bac bo van thanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ty nang x ho. hieu van bac bo van thanh vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty nang x ho. hieu van bac bo van thanh vi ((cua tre) OR (cua triet))*.