http://apesportal.eva.mpg.de/status/topic/status/population_dynamics

This is the web site for Ape Populations Environment Surveys. It applies demographic concepts to populations of gorillas and other anthropoid apes.

http://www.worldatlas.com/aatlas/populations/ctypopls.htm

This is the World Atlas site containing "[a]n interactive list of countries including their (2012–2014 estimated) populations, as well as land sizes and densities."

http://www.census.gov/popclock/

The U.S. Census Bureau U.S. and World Population Clock is consistent with 2010 Census data and the most recent national population estimates.

http://www.bbc.co.uk/schools/gcsebitesize/geography/population/population_change_structure_rev5.shtml

A BBC site that discusses population structure, including population pyramids.

http://www.stats.ox.ac.uk/~mcvean/slides7.pdf

A site maintained by Oxford University. It provides an in-depth exploration of structural variation in populations of human and nonhuman species.

http://www.ethnicity.ac.uk/medialibrary/briefings/dynamicsofdiversity/what-makes-ethnic-group-populations-grow-age-structures-and-immigration.pdf

This University of Manchester site focuses on ethnic and age structures. "By following the changing age structure of each ethnic group—the number of people at each age—from the 2001 Census to the latest Census in 2011, we have been able to estimate the contribution to population growth of international migration, births and deaths."

http://www.geog.cam.ac.uk/research/centres/campop/occupations/

This is the site of the Cambridge Group for the History of Population and Social Structure. " research program directed by Leigh Shaw-Taylor and Tony Wrigley aims ultimately to reconstruct the evolution of the occupational structure of Britain from the late medieval period down to the early twentieth century. The project has been designated as a British Academy Research project since 2007 (renewed for a further five years in 2012).

http://www.cdc.gov/nchs/nvss/about_nvss.htm

http://www.cdc.gov/nchs/nvss.htm

These two sites are posted by the National Vital Statistics System (NVSS) of the U.S. Centers for Disease Control and Prevention. "The National Vital Statistics System is the oldest and most successful example of inter-governmental data sharing in Public Health and the shared relationships, standards, and procedures form the mechanism by which NCHS [National Center for Health Statistics] collects and disseminates the Nation's official vital statistics."

http://popindex.princeton.edu/Articles/Weed.html

This is an article about vital statistics in the United States.