Harding, L. (2017). A very expensive poison: The assassination of Alexander Litvinenko and Putin's war with the West. Vintage Books, a division of Penguin Random House LLC.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Harding, Luke. A Very Expensive Poison: The Assassination of Alexander Litvinenko and Putin's War with the West. New York: Vintage Books, a division of Penguin Random House LLC, 2017.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Harding, Luke. A Very Expensive Poison: The Assassination of Alexander Litvinenko and Putin's War with the West. Vintage Books, a division of Penguin Random House LLC, 2017.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.