Perhaps you should try some spelling variations:
thanh va » thanh van, hanh va, thanh ha
thanh vi » hanh vi, thanh ve, nhanh vi
te sach » toc sach
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang co » nang cao, nang doc, nang noi
bo van » vo van, so van, do van
nang o » nang ho, nang ro, nang x
cac bo » bac bo, cac co

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 ty ((nang o) or (nang co)) hai. hieu va cac bo van ((thanh vi) OR (thanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang o) OR (nang co)) hai. hieu va cac bo van ((thanh vi) OR (thanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang o) or (nang co)) hai. hieu va cac bo van ((thanh vi) OR (thanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang o) or (nang co)) hai. hieu va cac bo van ((thanh vi) OR (thanh va)) cua tre*.