Aircraft Contrails: Where does the moisture come from?

Be warned: any mention of ‘chemtrails’ will result in comments being ditched in the bit bucket.

Roger Clague writes in suggestions:

Contrails, does the water vapour come from the burnt fuel or the air?

According to Nasa 99.9% is from the air 0.01% from the burnt fuel.

http://science-edu.larc.nasa.gov/contrail-edu/science.php

“Nearly all of the contrail is created from the moisture in the atmosphere. “
Justified by R.G.Knollenberg(1972) paid by Nasa
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469%281972%29029%3C1367%3AMOTGOT%3E2.0.CO%3B2
“There are at least four orders of magnitude more ice present in the contrail core than the Sabreliner originally exhausted!”
A later Nasa paper says
http://journals.ametsoc.org/doi/pdf/10.1175/JAM2325.1
Atlas, Wang and Duda ( 2006)
“The average ice water per meter along the length of the contrail is 1.6 104 g m 1 , some three to four orders of magnitude greater than the water vapor released by typical jet aircraft, also similar to previously reported values.”

Duda says elsewhere:
http://www-pm.larc.nasa.gov/site/doc-library/147-Duda.Controller.09.pdf
“Like contrails, the cloud that forms on your breath during a cold day is a mixing cloud.”
Contrails are like breath on a cold day. Water vapour is from the breath not the ambient air.
Other government bodies the EPA and FAA agree with Nasa and puts it very clearly:
http://www3.epa.gov/otaq/regs/nonroad/aviation/430f00005.pdf
https://www.faa.gov/regulations_policies/policy_guidance/envir_policy/media/contrails.pdf
“Jet engine exhaust provides only a small portion of the water that forms ice in persistent contrails. Persistent contrails are mainly composed of water naturally present along the aircraft flight path.”
However all other sites I have found say all the water is from the burnt fuel.
http://contrailscience.com/contrails-are-condensation-but-not-like-your-breath
https://en.wikipedia.org/wiki/Contrail
cliffmass.blogspot.com/2013/08/chemtrails-versus-contrails-do.html

http://www.aero-net.info/fileadmin/aeronet_files/links/documents/DLR/Schumann_Contrails.pdf

Schumann is a world expert. He has 135 references but does not include Knollenberg(1972)

Is Nasa/EPA/FAA right about contrails?
If not why not?