From the description of Autograph letter signed : London, to W.A. Knight, 1887 July 11. (Unknown). WorldCat record id: 270862619From the description of Autograph letter signed : London, to W.A. Knight, 1891 July 6. (Unknown). WorldCat record id: 270862625From the description of Autograph letter signed : London, to W.A. Knight, 1891 Dec. 15. (Unknown). WorldCat record id: 270862635From the description of Autograph letter signed : London, to W.A. Knight, [n.d.] "Sunday." (Unknown). WorldCat record id: 270862660From the description of Autograph letter signed : London, to W.A. Knight, 1899 June 1. (Unknown). WorldCat record id: 270862650From the description of Autograph letter signed : London, to W.A. Knight, 1899 May 19. (Unknown). WorldCat record id: 270862646From the description of Autograph letter signed : London, to W.A. Knight, 1901 Mar. 16. (Unknown). WorldCat record id: 270862656From the description of Autograph letter signed : Edinburgh, to W.A. Knight, 1899 July 12. (Unknown). WorldCat record id: 270862652From the description of Autograph letter signed : London, to W.A. Knight, 1891 July 14. (Unknown). WorldCat record id: 270862630