Luton have made their ninth summer signing following the arrival of winger Danny Green.
Notts County have signed Togo international Mawouna Amevor on a two-year deal.
Crystal Palace manager Ian Holloway has played down the prospect of Wilfried Zaha returning to the club on loan in January.
Reports claim Manchester United are prepared to send Zaha out on loan in the New Year owing to his failure to break into David Moyes' first-team plans since his arrival from Palace in the summer.
Zaha, who signed for United last January, but was immediately loaned back to Palace, has made just one appearance for the Red Devils in the Community Shield this term.
A host of clubs, including Palace, have been linked with a move for Zaha if he becomes available in January, but Holloway concedes a bid to bring the England Under-21 international back to Selhurst Park is unlikely.
"David Moyes has his own issues at Manchester United, so if we were to go shouting about wanting him back on loan, I don't think we will ever get him back," Holloway told the South London Press.
"Besides, we have options [on the wings] - Jason Puncheon can play either side and in the pocket as well as in central midfield. Yannick Bolasie is coming back and will do well. It is all about having a squad that is strong enough to make changes and sustain good performances.
"At the moment, we are not beating people. [Jimmy] Kebe might have the chance to do that. And we know Jerome Thomas can."