This is a book reference [1]. Okuda and Okuda remarked this previously [1].

This is a journal article reference [2]. Wilcox remarked this previously [2].

This is a newspaper article reference [3]. Di Rado remarked this previously [3].

This is a newspaper article reference without an author [4]. Activision suing over Star Trek remarked this previously [4].

This is a magazine article reference [5]. Di Rado remarked this previously [5].

This is a book chapter reference [6]. James remarked this previously [6].

This is a web page reference [7]. Lynch remarked this previously [7].