Perhaps you should try some spelling variations:
tan hanh » tan thanh, tang hanh, toan hanh
hieu van » thien van, lieu va, hieu ve
nano bac » tao bac, bang bac, dan bac
sach tu » sach thu, cach tu, sach ty
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
nano xa » nano va, nano cau, nano dua
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: tu sach tu ((nano xa) or (nano bac)) hoi. ((hieu van) or (hieu va)) cao duc tan hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu ((nano xa) OR (nano bac)) hoi. ((hieu van) OR (hieu va)) cao duc tan hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach tu ((nano xa) or (nano bac)) hoi. ((hieu van) or (hieu va)) cao duc tan hanh vi cuu tre*.