National Environmental Education Development. National Park Foundation. (1971). Adventure in environment: Teacher's guide. Silver Burdett.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)National Environmental Education Development. National Park Foundation. Adventure in Environment: Teacher's Guide. Morristown, NJ: Silver Burdett, 1971.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)National Environmental Education Development. National Park Foundation. Adventure in Environment: Teacher's Guide. Silver Burdett, 1971.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.