I try to take this with me in my pocket, if I'm forewarned enough.
If not, having it saved in my phone and knowing how to make a simple battery in order to recharge it if necessary (and assuming I'm able to clandestinely get hold of writing materials to hurridly copy out the gist of the text) should do the trick.
Maybe I should start learning it by rote, too.
Also, I don't think it's on there, but I could probably have a decent shot at coming up with a printing press, and so long as I can find a source of germanium, a variety of basic electronic components.
I could probably also, with the help of a moderately competent blacksmith and some time spent producing progressively more precise tooling, come up with a reasonably good (bio-)diesel engine, bypassing all of that steam-powered and highly inefficient gasoline nonsense, and once that was in place as a primary generator and a good source of copper secured, try to move on to a renewably-generated electricity based energy economy. Think of all those wind and water mills that hadn't yet fallen into disrepair... stick a decent generator on each one, and we're in business.
And once the electronics are refined to a practical level, the efficiency both of the electrical systems and the diesel motors can be jacked up by at least a third. Also, bring in LEDs before incandescent lights are even thought of, and promote Passivhaus type building rather than just chucking loads of energy at heating/cooling leaky buildings.
I would also leave a stark warning of the potential environmental destruction that could be wreaked by overuse of either tech - the smoke doesn't just disappear into the aether, and there's only a limited amount of generating capacity that can be squeezed out of the environment (and even if we come up with decent solar collectors to cover shortfall, it is dumping energy in unnaturally concentrated and distributed patterns, when a lot of it may have just been reflected into space) - to prevent reaching a level of overdependence.
The third part of this world saving, utopia ushering trifecta - assuming we've done the whole "don't drink where you shit" and pencillin/pasteurisation/cowpox/wash your goddamn hands already gig - would be working towards a revolution in midwifery, birth control and childcare. You don't need to pump out six or more kids as rapidly as possible when there's a good guarantee that both they and their mother are going to survive to see a good clutch of grandchildren, and when mechanisation will ultimately save the majority of citizens from a life of manual toil in the fields, home or factory. We didn't come to that realisation for a couple of generations after the fact... hence considerable overpopulation (and unemployment) that's now going to be rather difficult - and take several generations - to get rid of without some natural or man-made mass die-off... if we ever manage it at all.
(From a personal perspective, on that front, I'd try to get some kind of premature birth care going on (I was 3 weeks early and plastic-boxed; wouldn't have survived prior to about 1920), and diagnosis/treatment for pulmonary embolism, uterine bleeding and other potentially fatal complications (the former of which I have been involved in diagnostic scans for... though as that required a rather complicated, bulky electronic device, and a good supply of radioactive tracer, some lateral thinking will be required rather than straight application of 20th/21st century technology) in order to bring about that result)
