If you are a student or works at a college, this would be really easy and you can find amazing information of libretto using the school's online database. Database offers information that you can't find online.
You can buy one from the Metropolitan Opera Shop. You can find them in New York City or online.
Libretto is the text to an Opera.
Libretto.
The libretto is the text - the lyrics - which the composer adds music to. The score is the music on which the libretto is sung.
"Libretto" is the technical term for the text and lyrics.
The text of an opera is called a "libretto". It often contains both the original text (often in Italian or German) and the translation, commonly in English.
The libretto.
The 'libretto' is the words or story of the opera.
Plural form of Libretto is Libretti.
Toshiba Libretto was created in 1996.
You can find it here, at the link "Scarica il libretto di istruzioni" http://www.bosch-elettrodomestici.it/it/prodottischeda.aspx-productid-432.htm
I don't know I'm so sorry!