Tri mind control

I use old school military cadence to keep my legs moving and in time. It may be cheesy but works for me

Reading a manual? Uhh... Good luck with that. No offence but that's pretty much impossible for someone to teach you motivation through a manual. 

I look at it as, if I want my goal bad enough, I can keep moving my legs. If my legs slow down and I let them, I obviously don't want to reach that goal enough.

P.S. A good method to running, however, is to try to completely zone out, then you don't have to think about anything. 

The OP didn't say anything about motivation.  He said: deal with the psychological aspects of endurance sports.  Need a manual how to tell the head to "shut up" while the legs keep moving .....

That is not the same as motivation.  You can still need this manual and not have issues with motivation.  To me, it sounds like the OP is looking for manuals/articles/posts/blogs/etc that deal with suppressing or handling the negative thoughts that eventually EVERYONE has in endurance events.

That being said, I don't know of any .  Just wanted to clarify what I think you're looking for.

I don't have any book recommendations (I'm interested too); but for what it's worth, here are some of my personal tricks to focus my mind on things other than pain:

1) When all else fails, I count. I find this to be simple and surprisingly effective. Whether it is strides while running or pedal revolutions on the bike, counting out a couple of hundred will put a few minutes in the rearview mirrow.

2) Problem solving. I'm normally pretty decent at performing calculations in my head, but I seem to take longer and need to concentrate more while exercising. Figuring out what my next mile time needs to be for an overall pace of X or even just multiplication along the lines of 89 x 21 will take my mind off the immediate task at hand.

3) I talk to myself...out loud (Warning: If you try this, be cognizant of your surroundings...not that I've ever received any strange looks or anything). Sometimes I lie to myself to try to promote a positive vibe ("Feeling good! You can keep this up all day!"). Other times, my messagge is more along the lines of HTFU ("Come on, [expletive deleted], you're better than this! Let's go!").

4) I think about long-term goals (my next race) or short-term goals (that tree down the road or that potential pace booty in the distance )

I haven't found any rhyme or reason why one method works one day and another works the next, so YMMV.

Good luck & Boiler Up!

Outside endurance sports, check out The Fighter's Mind, by Sam Sheridan. The author interviews several MMA fighters.

Try a few books by people who have overcome adversity. That puts our training in perspective. Iron Heart is about an ironman finisher with a hart transplant. Matt Long he NYC firefiter who was hit by a bus, The Long Run.

I read these a few years back so I don't remember the specifics but they might be worth looking into.

  Brain Training for Runners - Matt Fitzgerald

  In Pursuit of Excellence - Terry Orlick

Personally, I don't tell my head to shut up, it's quite the opposite! I sing songs, re-enact movie scenes, write open letters to friends and family, conduct (VERY IMAGINARY) post race interviews with myself as the winner, think about place I want to travel, remember places I have traveled, etc, etc. Those space-outs are one the things I love about this the MOST - the longer the distance the better, more time in outer space. That quiet mind you're fighting with needs to be activated while your body goes into autopilot and executes what you've trained it to do.

I've seen the advice that the mantra should always be something to the tune of "can I go any harder?" but I have to disagree with it, personally. You have all the time in the world to train your body to go *exactly* as hard as it can, and questions about "how much harder" or "was that too hard" are asked and answered in between training sessions. The race is about execution of that training, not a time to start playing with pace. The tweaks between training sessions shouldn't be HUGE...while training you should still be mentally nestling into that more and more familiar place between your ears while your body goes to work.  

I don't know of any books but self talk helps me.

Sometimes I tell myself to 'be a Kenyan' over and over again when I am running.

Sometimes I sing Pink Floyd's "Welcome to Machine" to myself. (I don't know all of the words) but the point is that machines don't submit to pain or discomfort. They go until they're done or they break.

When running, focusing on the moving shoes of a runner right in front of you can help you zone into a cadence. If there is no one ahead of you, focus on the road about 5 feet in front of you instead of looking too far into the distance. Looking into the distance on a race can discourage you.

Swimming, well, I just repeat Dori's famous line from Finding Nemo... "Just keep swimming....swimming, swimming."  It's corny but it works.

At the USAT Certification Course, they had an entire session dedicated to this!

Here are a few references from that presentation:

The New Toughness Training for Sports -Loehr, Jansen and Evert

Peak Performance: Mental training techniques of the world's greatest athletes - Garfield and Bennett

Mental toughness for sports -Loehr

The Sports Psychology Handbook - Murphy

Mental Training for Peak Performance - Ungerleider

Brain Training for Runners - Fitzgerald