Separated at birth

As I mentioned earlier, I am fairly confident that Nikolaus Weise and Nikolaus Wyse are the same person, although they have separate entries in the Personennamendatei of the Deutsche Nationalbibliothek (PND 119866811 and PND 119875667, respectively). Occasionally I'll come across other authors where the names, titles, and dates of publication suggest that a single author's name has been recorded in two different forms. This one, for example, looks like a duplicate entry in VD16:

• Cöllen, Lukas von - PND 119643081. Author of VD16 ZV 3751, 3752. ZV 3751 is ALmanach vnde Practica vp dat Jar...M.D.LXXX, Bibliograph. Nachweis: BC 2213.
  
• Köln, Lukas von - PND 119730855. Author of VD16 ZV 2550, 9095. ZV 9095 is ALmanach vnde Practica vp dat Jar...M.D.LXXX, Bibliograph. Nachweis: BC 2213.
  

It can also happen when an author's works show up in both VD16 and VD17. In this example, both Werner Hartmann and "Berner Hartmann" describe themselves as disciples of Leonhardt Thurneysser zum Thurn:

• Hartmann, Werner - PND 119699729. Author of VD16 ZV 7384 (PROGNOSTICON Astrologicum, Auff das Jahr...M.D.XCVII). Erfurt: Jakob Singe, 1597
• Hartmann, Berner - PND 121734994. Author of VD17 23:285570G (Deutsche Practica/ Auff das Jahr ... M.DC.X). Erfurt: Singe, [1609]