If you look at Rudling 2, 20, you'll see an author with a pseudonym. In the biblio, the pseudonym is handled like this:

<biblStruct>
                      <monogr>
                        <author><name reg="Gunnarson, Karl: see Schulze, Karl Gunnar">Karl Gunnarson see Schulze, Karl Gunnar</name></author>
                        <title></title>
                        <imprint></imprint>
                      </monogr>
                    </biblStruct>

                  <biblStruct>
                    <monogr>
                      <author><name reg="Schultze, Karl Gunnar (pseud. Karl Gunnarson)">Karl Gunnar Schultze (pseud. Karl Gunnarson)</name></author>
                      <title level="m">På Kanadas prärier</title>
                      <imprint>
                        <pubPlace>Stockholm</pubPlace>
                        <publisher>Folket i Bilds Förlag</publisher>
                        <date value="1939">1939</date>
                      </imprint>
                    </monogr>
                  </biblStruct>