You can add a new person with the name "Al-Ahsan Talukder, Debabrata Kumar Karmokar, Khaled Mahbub Morshed", or you can "Al-Ahsan Talukder, Debabrata Kumar Karmokar, Khaled Mahbub Morshed" with a person entry that is so far only been referred to by another name (such as a former name or an alias name).