Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, ban thanh
nham thuc » nhan thuc, nam thuc, pham thuc
thanh vi » hanh vi, thanh va, thanh ve
nang mai » nang tai, lang mai, nang cai
nham thu » nam thu, pham thu, nhan thuc
so cach » so sach, co cach, loi cach
hieu ve » hieu va, hieu van
cach tu » cach thuc
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
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: so cach tu ((nang mai) or (nang ma)) hoi. hieu ve ((nham thuc) OR (nham thu)) dan thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so cach tu ((nang mai) OR (nang ma)) hoi. hieu ve ((nham thuc) OR (nham thu)) dan thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so cach tu ((nang mai) or (nang ma)) hoi. hieu ve ((nham thuc) OR (nham thu)) dan thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: so cach tu ((nang mai) or (nang ma)) hoi. hieu ve ((nham thuc) OR (nham thu)) dan thanh vi cua tre*.