Broken is_page

function wga_lgmgm_styles() {
    if (is_page(league-management)) {
        wp_register_style('lgmgm-style', get_template_directory_uri() . '/wga-lgmgm/css/leagueManagement.css');
        wp_enqueue_style('lgmgm-style');
    }
    else {
        wp_deregister_script('lgmgm-style');
    }
}
add_action('wp_enqueue_scripts', 'wga_lgmgm_styles');