there are tons of applied science popular books out there, but real science texts are generally dry, hair shirt reading.
my go to foundation text is vladimir zatsiorski’s ‘science and practice of strength training‘ this used to be penn state’s survey course text, i believe.
next would be ‘principles and practice of resistance training’ by michael stone, meg stone and william sands (east tennessee state s&c dept is top notch)
an nsca membership gets you access to all their strength and conditioning journals and more papers than you could ever want or need. the library is digital now, so finding papers on topics of interest is pretty easy.