Não informado. (2008). Communications of the Department of Chemistry. Bulgarian Academy of Sciences.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Communications of the Department of Chemistry. Sofia: Bulgarian Academy of Sciences, 2008.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Communications of the Department of Chemistry. Bulgarian Academy of Sciences, 2008.
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