Converter from researchmap CSV file to BibTeX file. only english paper

rmap2bib.rb

#! /usr/bin/env ruby
# coding: utf-8
require 'csv'

csvfile = ARGV[0] || "paper.csv"
bibfile = ARGV[1] || "paper.bib"
csv = CSV.read(csvfile, headers: true, encoding: 'Shift_JIS:UTF-8')
bib = File.open(bibfile, "w", encoding: "UTF-8")
csv.each do |line|
  label = line['タイトル(英語)'][0..8].gsub(' ','_') + line['出版年月']
  author = line['著者(英語)']
  title = line['タイトル(英語)']
  journal = line['誌名(英語)']
  volume = line['巻']
  number = line['号']
  startp = line['開始ページ']
  endp = line['終了ページ']
  year = line['出版年月'][0..3]
article = <<END
@article{#{label},
  author = "#{author}",
  title = "#{title}",
  journal = "#{journal}",
  volume = "#{volume}",
  number = "#{number}",
  pages = "#{startp}--#{endp}",
  year = "#{year}"
}

END
  bib.puts article
end