Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
tru nang » tra nang, tri nang, thi nang
duc van » duc va, duc tan, duc manh
cau duc » cao duc, cau luc, chu duc
van cau » van dau, van hau, van chat
su sach » so sach, vu sach
tu nang » tu nong, tu nano, tu lang
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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 ((tu nang) or (((tru nang) OR (truc nano)))) xa hoi. hieu van cau duc van thanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((tu nang) OR (((tru nang) OR (truc nano)))) xa hoi. hieu van cau duc van thanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((tu nang) or (((tru nang) OR (truc nano)))) xa hoi. hieu van cau duc van thanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((tu nang) or (((tru nang) OR (truc nano)))) xa hoi. hieu van cau duc van thanh vi cuu tre*.