I have solved the issue by myself. I am posting the solution here in case if someone gets the same problem.
function wpse15677455_redirect() {
$ref = wp_get_referer();
if (is_page(1911) && $ref !== "https://www.example.com/contact"){
wp_redirect( get_home_url() );
}
else if(is_page(1269) && $ref !== "https://www.example.com/contact-form-2"){
wp_redirect( get_home_url() );
}
else if(is_page(1825) && $ref !== "https://www.example.com/contact-form-3"){
wp_redirect( get_home_url() );
}
else if(is_page(1623) && $ref !== "https://www.example.com/contact-form-4"){
wp_redirect( get_home_url() ); exit();
};