@Override
    public void run() {
        for (Citation c : citations.getCitations()) {
            io.println(c.getId() + ": " + c.getTitle());
        }
        
        Integer command = -5;
        try {
            command = io.getInteger("Give id of the article to remove (or -1 to cancel): ");
        }
        catch (NumberFormatException e) {
            System.out.println("Error: id's are integers.");
        }
        
        if (command >= 0) {
            if (citations.removeCitation(command)) {
                io.println("Citation was removed succesfully!");
            }
            else {
                io.println("Citation with a specified id wasn't found and therefore not deleted. Try again.");
            }
        }
        else {
            io.println("Removal cancelled.");
        }
    }