SELECT id, ort, fachwort, (
6368 * SQRT(2*(1-cos(RADIANS(lng)) *
cos(0.20894662925856) * (sin(RADIANS(lat)) *
sin(0.83377886479566) + cos(RADIANS(lat)) *
cos(0.83377886479566)) - sin(RADIANS(lng)) * sin(0.20894662925856)))) AS entfernung
FROM literatur WHERE
6368 * SQRT(2*(1-cos(RADIANS(lng)) *
cos(0.20894662925856) * (sin(RADIANS(lat)) *
sin(0.83377886479566) + cos(RADIANS(lat)) *
cos(0.83377886479566)) - sin(RADIANS(lng)) * sin(0.20894662925856))) <= 25
ORDER BY entfernung