Missing lessons on Blues Bottleneck

I tried clicking a link from the page "Where do I Start" and it led to a page with no listed lessons. It was called Blues Bottleneck, Slide for Beginners. It's not a huge deal since there are other slide lessons available. Just thought I'd mention it. The lesson was by Bernie Ferguson. The link is at the bottom of the page under technigues and there are several other links that have missing lessons too.