Reaxys does not directly provide spectra, but does cite and link to the publications in which spectra are found.
Spectra in the SDBS are mostly unique to that database, run in the laboratories of the National Metrology Institute of Japan. The FAQ suggests this citation:
SDBSWeb : http://riodb01.ibase.aist.go.jp/sdbs/ (National Institute of Advanced Industrial Science and Technology,date of access)
Check this format against the rules for Internet databases in your preferred citation style.