Não informado. (1914). Contributions from the Department of Botany. Pennsylvania State College, Department of Botany.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Contributions from the Department of Botany. State College, Pa: Pennsylvania State College, Department of Botany, 1914.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Contributions from the Department of Botany. Pennsylvania State College, Department of Botany, 1914.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.