I love Babji ;senior in lineage Parmahansa Yogananda

of Self Realization Fellowship
As the article suggests, in the last paragraph,-Autobiography of a Yogi-
And of course, The Ascended Masters of the Middle East

This is a type of Kriya Yoga, and meditation 1-8 hours at a time
I struggled for a year to get to one hour and even after discplining the body and mind sometimes it is not a peaceful hour

But mostly now it is done with ease...depends on the day and the thoughts
I go at 7am and leave at 8am on weekdays- but the meditation goes from 7am-9am every day at San Diego Temple

On Easter and Christmas there are 3 hour and 8 hour meditations respectively.
http://www.yogananda-srf.org/
Daya Ma runs the SRF now