} else if (l.equalsIgnoreCase("date")) {
html.append(join(f.dates()));
} else if (l.equalsIgnoreCase("type")) {
html.append(join(f.types()));
} else if (l.equalsIgnoreCase("format")) {
html.append(join(f.formats()));
} else if (l.equalsIgnoreCase("identifier")) {
html.append(join(f.identifiers()));
} else if (l.equalsIgnoreCase("source")) {
html.append(join(f.sources()));
} else if (l.equalsIgnoreCase("language")) {