documentclass{article}
usepackage[x11names, rgb]{xcolor}
usepackage[utf8]{inputenc}
usepackage{tikz}
usetikzlibrary{snakes,arrows,shapes}
usepackage{amsmath}
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begin{document}
pagestyle{empty}
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enlargethispage{100cm}
% Start of code
begin{tikzpicture}[>=latex',line join=bevel,]
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node (Wollongong) at (487bp,594bp) [draw=lightblue2,fill=lightblue2,ellipse] {Wollongong};
  node (PDP-11 Sys V) at (884bp,306bp) [draw=lightblue2,fill=lightblue2,ellipse] {PDP-11 Sys V};
  node (Interdata) at (258bp,594bp) [draw=lightblue2,fill=lightblue2,ellipse] {Interdata};
  node (2*8 BSD) at (221bp,162bp) [draw=lightblue2,fill=lightblue2,ellipse] {2.8 BSD};
% CODE REMOVED TO SAVE SPACE
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end{tikzpicture}
% End of code

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end{document}
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