@conference{825036,
  author = {S Waltman and K Petrov and E Dlugokencky and M Arbore and M Fejer and F Tittel and Leo Hollberg},
  title = {Measurement of <sup>13</sup>CH<sub>4</sub>/<sup>12</sup>CH<sub>4</sub> Ratios in Air Using Diode-Pumped 3.3 &#965;m Difference-Frequency Generation in PPLN},
  year = {1997},
  month = {1997-01-01 00:01:00},
  publisher = {IEEE Summer Topicals  , Quebec, 1, CA},
  language = {en},
}