Hindley's Basic Simple Type Theory is accessible and comes from the horse's mouth: http://books.google.co.uk/books/about/Basic_Simple_Type_Theory.html?id=XgyI7v

Hindley's Basic Simple Type Theory is accessible and comes from the horse's mouth: http://books.google.co.uk/books/about/Basic_Simple_Type_Theory.html?id=XgyI7vY0BLgC&redir_esc=y http://books.google.co.uk/books/about/Basic_Simple_Type_Theo....