(1991). Chemical emergency preparedness and prevention technical assistance bulletin: Cameron County, Texas ; Bucks County, Pennsylvania ; Harford County, Maryland ; Dallas County, Texas.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Chemical Emergency Preparedness and Prevention Technical Assistance Bulletin: Cameron County, Texas ; Bucks County, Pennsylvania ; Harford County, Maryland ; Dallas County, Texas. 1991.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Chemical Emergency Preparedness and Prevention Technical Assistance Bulletin: Cameron County, Texas ; Bucks County, Pennsylvania ; Harford County, Maryland ; Dallas County, Texas. 1991.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.