public String AddAdditionalOpacPpns() {
StringTokenizer tokenizer = new StringTokenizer(this.additionalOpacPpns, "\r\n");
while (tokenizer.hasMoreTokens()) {
String tok = tokenizer.nextToken();
try {
ConfigOpacCatalogue coc = new ConfigOpac().getCatalogueByName(opacKatalog);
IOpacPlugin iopac = (IOpacPlugin) PluginLoader.getPluginByTitle(PluginType.Opac, coc.getOpacType());
Fileformat addrdf = iopac.search(this.opacSuchfeld, tok, coc, this.myPrefs);
if (addrdf != null) {
this.myDocStruct.addChild(addrdf.getDigitalDocument().getLogicalDocStruct());