What tense should we use when referring to a paper or experiments from other researchers? While writing the literature review section, I am confused about which tense should I use (past, present perfect, or present) while referring to other people's work.

I understand that established facts are presented in the present tense.
Work done is presented in past or present-perfect tense.
But in what tense should I define their (i) system model, (ii) experiments, and (iii) results so that the overall picture remains coherent and it does not seem like I am jumping from one tense to another?

What is the basis for using any of these tenses?
I present established facts in present tense, indeed. Other people's work that has led to these facts is presented in past or present-perfect. So for example: "Snippert et al. established a confetti mouse-line, and after doxycyclin administration showed that intestinal crypts tend towards clonality."