Lowest gravity on Earth's surface?

Lowest gravity on earth surface is near Sri Lanka based on the articles below.

• http://www.expertcore.org/viewtopic.php?f=13&t=3537&start=0&sid=4f7757b9c5105a7ba859ddc46c616102

• http://www.timeseye.com/2011/12/sri-lanka-best-place-for-space-port.html

A late 2013 research paper publish on Science Daily by Curtin University mentions that the point on the Earth's surface with the lowest gravity is Mount Huascarán in Peru.

The new gravity maps revealed the variations of free-fall gravity over Earth were much bigger than previously thought.

Earth's gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes, and largest near the North Pole.

According to http://en.wikipedia.org/wiki/Gravity_of_Earth#Comparative_gravities_in_various_cities_around_the_world Mexico City has the lowest gravity of any city. However the article doesn't mention mountain tops.