"Putrescine - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. मूल से 12 अक्तूबर 2012 को पुरालेखित. अभिगमन तिथि 26 May 2012.
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"Putrescine - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. मूल से 12 अक्तूबर 2012 को पुरालेखित. अभिगमन तिथि 26 May 2012.