Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
cham tuc » pham thuc, tham thuc, cham soc
cuu tre » cua tre, cau tren, cau treo
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
doan vi » doan va, don vi, doan thi
dan vi » don vi, dan va, gan vi
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky tang ma hoi. hieu ve ((cham tuc) or (nham thuc)) va ((dan vi) OR (doan vi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky tang ma hoi. hieu ve ((cham tuc) OR (nham thuc)) va ((dan vi) OR (doan vi)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky tang ma hoi. hieu ve ((cham tuc) or (nham thuc)) va ((dan vi) OR (doan vi)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky tang ma hoi. hieu ve ((cham tuc) or (nham thuc)) va ((dan vi) OR (doan vi)) cuu tre*.