Gaya APA
Helweg, Otto J.. (1984).
Water resources planning and management (text).
New York:
John Wiley.
Gaya Chicago
Helweg, Otto J..
Water resources planning and management.
text
New York:
John Wiley,
1984.
Tesis.
Gaya MLA
Helweg, Otto J..
Water resources planning and management.
text
New York:
John Wiley,
1984.
Tesis.
Gaya Turabian
Helweg, Otto J..
Water resources planning and management.
text
New York:
John Wiley,
1984.
Tesis.