code: public List<Citation> makeCitation(String... ids) {
  		CSLCitationItem[] items = new CSLCitationItem[ids.length];
  		for (int i = 0; i < ids.length; ++i) {
  			items[i] = new CSLCitationItem(ids[i]);
  		}
  		return makeCitation(new CSLCitation(items));
  	}
docs: Generates citation strings that can be inserted into the text. The
  method calls {@link ItemDataProvider#retrieveItem(String)} for each of the given
  IDs to request the corresponding citation item. Additionally, it saves
  the IDs, so {@link #makeBibliography()} will generate a bibliography
  that only consists of the retrieved citation items.
  @param ids IDs of citation items for which strings should be generated
  @return citations strings that can be inserted into the text
  @throws IllegalArgumentException if one of the given IDs refers to
  citation item data that does not exist