I employ a simple version of the bullet journaling method. I maintain an index at the beginning of the book where I add topics and the page numbers that I have information about it on. Still not ctrl-f speed of course, but I am not flipping through my notebook trying to find the right page. For your situation, I'll probably right down the job reference on the page of the day, and then add a `Job References` entry in the index and add the current page number beside it. At the end of each year, I'll digitize everything important for archival purposes (usually very little), and move over ongoing collections (like book list), to the next notebook.