LyX ⇒ Bibliography Error

[eugymodena]

hi! I have a problem with the bibliography of a document. I can not explain it in words, you better look at this picture:

LyX-Bibliography-Error.png (107.14 KiB) Viewed 1089 times

I wish that there was only in the text [1], and not that weird symbol. Even in the bibliography does not wish there was the word [SR] to the left.
What's the problem?

I'm sorry for my bad english but I'm italian.
Thanks!