function my_connection_types() {
    if ( !function_exists( 'p2p_register_connection_type' ) )
        return;

    p2p_register_connection_type( array(
        'name' => 'seminar_zu_termin',
        'from' => 'page',
        'to' => 'tribe_events',
        'cardinality' => 'one-to-many',
        'sortable' => 'from'
    ) );
}
add_action( 'wp_loaded', 'my_connection_types' );