Some 200 million people lived on Planet Earth at the start of the modern era. That number rose to 2.5 billion by 1950. At mid-2008, the population is now 7.0 billion and is expected to reach 9.0 billion...
Groundwater is of major importance to rural development in many countries of the world. As a result of its widespread distribution, low development cost, and generally excellent quality, it has been the...
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