% A4, two columns: saves paper, for reading at a desk.
% The references go in the outer margin of each column.
\documentclass[10pt,twocolumn]{article}
\usepackage[a4paper,hmargin=20mm,top=18mm,bottom=22mm,columnsep=9mm,
  marginparwidth=12mm,marginparsep=2.5mm]{geometry}
\input{phaedo-common}
\setlength\marginparpush{0pt}
\begin{document}
\twocolumn[\heading\vspace{2ex}]
\input{phaedo-text}
\end{document}