Doppler spectroscopy
...that Doppler spectroscopy was used to discover the first extrasolar planet in 1995 and has since been used to identify more than one hundred exoplanet candidates?
...that <b id="mwEfA"><a href="./Doppler_spectroscopy" id="mwEfE" rel="mw:WikiLink" title="Doppler spectroscopy">Doppler spectroscopy</a></b> was used to discover the first <a class="mw-redirect" href="./Extrasolar_planet" id="mwEfI" rel="mw:WikiLink" title="Extrasolar planet">extrasolar planet</a> in 1995 and has since been used to identify more than one hundred exoplanet candidates?