Imperial commander Wallenstein turns his campaign to the Baltic
coast: he takes Wismar, blockades Rostock harbour and in June,
begins to besiege Stralsund.
Citation:
Editors. "Wallenstein takes lands in northern Germany".
The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15979, accessed 21 May 2013.]