Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
tang tai » hang tai, dung tai, sang tao
tai khoa » da khoa, noi khoa
hieu va » hieu qua
vuc ban » vu ban, duc ban, cuc ban
cac vuc » cac nuoc, cac vung, cac cuoc
tu sach » thu sach, su sach, tu cach
ky tang » ky nang, ky dang, kho tang
te sach » toc sach
buu tre » cuu tre

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) ky tang tai khoa. ((hieu va) OR (lieu va)) cac vuc ban thanh tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky tang tai khoa. ((hieu va) OR (lieu va)) cac vuc ban thanh tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky tang tai khoa. ((hieu va) OR (lieu va)) cac vuc ban thanh tai buu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky tang tai khoa. ((hieu va) OR (lieu va)) cac vuc ban thanh tai buu tre*.