How have the courts treated the privilege against self-incrimination in questioning witnesses at a civil trial?

4 A substantial percentage of questions which witnesses refused to answer dealt with the witnesses' intentions to produce corporate documents. While the document-by-document questioning might resemble "harassment," those questions may have been justified by the prosecutor's need to make a record to challenge the assertions of privilege. It is well established that the privilege against self incrimination is personal and does not extend to corporate documents. Bellis v. United States, 417 U.S. 85, 88, 94 S.Ct. 2179, 40 L.Ed.2d 678 (1974).