Sources for the Eight-Volume Luther Sermons Edited by Lenker. Nowhere Does Luther Say "All Are Justified," Contrary to WELS Prof John Brug

That is even more true of his sermons.

Another source for all the Lenker sermons - 8 volumes - can be found here in several languages -

http://www.martinluthersermons.com/

I have the same Luther sermons, Lenker edition, posted here -

http://ichabodthegloryhasdeparted.blogspot.com/2012/04/sermons-of-martin-luther-lenker-edition.html

Some of Luther's sermons are also posted here - 

Our Redeemer Lutheran Church

Here are the printed sermons, including the House Postils

Pastor Paul Rydecki is a fountain of newly publishedworks on Lutheran Orthodoxy.

Pastor Paul Rydecki also has some of Luther's sermons posted 
on his congregation's website - here.

Project Gutenberg - various digital editions of the sermons and commentaries.