Dear Mr. Joseph,
First of all understand the different between Assignment & License.
License is an agreement provided by the author for a certain period of time with a good consideration.
Assignments is an agreement by the author to transfer the ownership of his / her work.
In a license agreement, even though e-publishing or ebook related contents are mute or silent. Definitely, publisher is on wrong foot to publish ebooks.
Feel free to contact me, if you need further details.
Corporate, Commercial & IP Lawyer
IP Lex Global Services
Mob: 0091-09902007635 / 34