Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
sach van » sach han, sach va, bach van
thanh vi » hanh vi, thanh va, thanh ve
truc van » truc va, thuc van, truc ban
cam truc » cau truc, nam truc, lam truoc
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach van ((nang xa) OR (nang ma)) hoi. ((hieu ve) or (hieu va)) cam truc van thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach van ((nang xa) OR (nang ma)) hoi. ((hieu ve) OR (hieu va)) cam truc van thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach van ((nang xa) OR (nang ma)) hoi. ((hieu ve) or (hieu va)) cam truc van thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach van ((nang xa) OR (nang ma)) hoi. ((hieu ve) or (hieu va)) cam truc van thanh vi cua tre*.