The migration took place in four distinct waves, beginning in the late 19th century and continuing to the present day.
They came in at least two distinct waves, from more than 20 countries.
Korean immigration to Hawaii came in two distinct waves in the 20th century.
Since then, Kazakh immigration has experienced three distinct waves.
European interest in the region then came in three distinct waves.
The German migration into Michigan was in two distinct waves.
Historically, there have been at least five distinct waves of human migration into Bhutan.
Historically, there have been at least five distinct waves of human migration into Bhutan: two ancient and three since the 19th century.
There were several distinct waves of ammonite evolution in Europe alone.
This migration occurred in five distinct waves over a period of 20 years.