Enger, Eldon D.
Environmental science : a study of interrelationships
McGraw-Hill, 2013
 Buku Teks
Enger, Eldon D.
Environmental science : a study of interrelationships
McGraw-Hill Higher Education, 2004
 Buku Referensi
Enger, Eldon D.
Environmental science : a study of interrelationships / Eldon R. Enger and Bradley F. Smith
McGraw-Hill, 2016
 Buku Teks
Enger, Eldon D.
Environmental science : a study of interrelationship
McGraw-Hill, 2010
 Buku Teks
Interrelationships between health programmes and socio-economic development
WHO, 1973
 Buku Teks