I listen to a couple of podcasts quite regularly – The Tim Ferriss Show and Revisionist History are both favourites of mine – and on one recently I heard someone say something that lodged in my head as being quite useful:
Regular review readily resolve random readings.
Ironically, I can’t remember where I heard this! But it is definitely good advice. I lost track of the number of times during my PhD where I thought, “Oh, I know this, now where…” and just couldn’t find the reference. You are hopefully doing better than me. You are hopefully managing your references well.
As you’re preparing for your viva, think about how you can summarise your key references. Think about how you can make a good overview of the key points of your argument and your results. You have a lot of this floating in your head, but if you systematically review what you’ve done and where it comes from the information and ideas will be easier to access. Make time to review things several times. It doesn’t have to be every day, but consider making it a habit.
Think about how you might do all this in a way that works for you – then do it.