BookStack/app/PageRevision.php

<?php namespace BookStack;

use Illuminate\Database\Eloquent\Model;

class PageRevision extends Model
{
    protected $fillable = ['name', 'html', 'text', 'markdown'];

    /**
     * Get the user that created the page revision
     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
     */
    public function createdBy()
    {
        return $this->belongsTo('BookStack\User', 'created_by');
    }

    /**
     * Get the page this revision originates from.
     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
     */
    public function page()
    {
        return $this->belongsTo('BookStack\Page');
    }

    /**
     * Get the url for this revision.
     * @return string
     */
    public function getUrl()
    {
        return $this->page->getUrl() . '/revisions/' . $this->id;
    }

}