Hello Sener,

You must comment out the lines which enqueue those files in the parent theme.

It is the enqueue.php file located in the /inc folder.

Look on line 15. Comment it out by adding two // before the line. Like so,

//wp_enqueue_style( 'integral_googlefonts', 'https://fonts.googleapis.com/css?family=Open+Sans:100,300,400,600,700,700italic,600italic,400italic|Cabin:400,500,600,700|Montserrat:400,700');