Bubble Diagram ( See Figure )

\documentclass[bordet = 5pt, tikz]{standalone}
\usetikzlibrary{shapes}
\usetikzlibrary{arrows}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}

\begin{document}

\begin{tikzpicture}[
  node distance = 2cm,
  bubble/.style = {draw, ellipse, minimum width = 1.5cm, minimum height = 1.0cm},
  line/.style = {-latex'},
  ]
  % bubbles
  \node[bubble] (B1) {Bubble 1};
  \node[bubble, above right = of B1] (B2) {Bubble 2};
  \node[bubble, below right = of B1] (B3) {Bubble 3};
  % lines
  \draw [line] (B1) -| ($(B2.west) + (-0.3,0)$) -- (B2.west);
  \draw [line] (B1) -| ($(B3.west) + (-0.3,0)$) -- (B3.west);
\end{tikzpicture}

\end{document}

\documentclass[a4paper,12pt]{article}
\usepackage{tikz}

\tikzset{every picture/.style={line width=1pt}} 
\begin{document}
\begin{tikzpicture}[x=0.75pt,y=0.75pt,yscale=-1,xscale=1]
\draw    (155.13, 153.5) circle [x radius= 76.13, y radius= 43.5]  ;
\draw    (398.63, 82) circle [x radius= 76.13, y radius= 43.5]  ;
\draw    (231.25,153.5) -- (295.5,154) ;
\draw    (295.5,154) -- (295.5,82) ;
\draw    (295.5,226) -- (295.5,154) ;
\draw    (400.63, 226) circle [x radius= 76.13, y radius= 43.5]  ;
\draw    (295.5,82) -- (322.5,82) ;
\draw    (295.5,226) -- (322.5,226) ;
\draw  (311,77) -- (323,82) -- (311,87) ;
\draw   (313,221) -- (325,226) -- (313,231) ;
\draw (147,152) node  [align=left] {Bubble 1};
\draw (397,81) node  [align=left] {Bubble 2};
\draw (401,225) node  [align=left] {Bubble 3};
\end{tikzpicture}

\end{document}