Greg DePersio has 13+ years of professional experience in sales and SEO and 3+ years as a writer and editor. Robert Kelly is managing director of XTS Energy LLC, and has more than three decades of ...

Survey sampling and estimation methods form the cornerstone of modern statistical inference, underpinning research across the social, medical, and natural sciences. At their heart, these methods ...

Note: This report was updated on Dec. 30, 2015 to reflect the January-July 2015 National Health Interview Survey estimates released on December 1, 2015. Telephone surveys face numerous challenges, but ...

Revision of Chapter 14.1 of the API Manual of Petroleum Measurement Standards (MPMS) was published in June 2001. This revision is the result of 7 years of an extensive natural gas sampling methods ...

The World Health Organization (WHO) warns that air pollution is of great concern and impacts health in many ways. To better the situation, it’s necessary to focus on air quality. However, when ...