If you’re ready to submit a scientific paper, you will have read 100 related papers.
Why 100? Well that advice has no basis more reliable than my own meandering experience. It’s my take on what it takes these days to be well versed on a specific topic and its broader background.
A typical scientific paper these days includes 30–50 references. Personally, I’ve gone as low as 24 and as high as 77. Twenty years ago, these numbers would’ve been lower, perhaps half as many. But rather than dwell on issues of inflation of the academic coin, we’ll just stick with 30–50 papers as our rough guess for now.
By the time you’re writing your own paper, you should’ve read more papers than you cite. And if you do the math, I’m perhaps implying that you should read 2–3 papers for every one that gets cited. Explore the literature beyond its essentials, but only so far before you reach a point of diminishing returns. Reasonable advice, right?