1. Filesystem Hierarchy Standard (FHS) Group (2015). Filesystem Hierarchy Standard, Version 3.0. The Linux Foundation. Section 3.2, "/bin : Essential user command binaries," specifies that /bin contains essential commands, including rm. (See page 10, https://refspecs.linuxfoundation.org/FHS3.0/fhs-3.0.pdf).
2. MIT Computer Science and Artificial Intelligence Laboratory (2020). The Missing Semester of Your CS Education: Lecture 2 - Shell Tools and Scripting. This university courseware details the standard Unix/Linux filesystem, explaining that /bin holds essential programs like ls, cp, and rm. (See course notes: https://missing.csail.mit.edu/2020/shell-tools/).
3. Bovet, D. P., & Cesati, M. (2005). Understanding the Linux Kernel, 3rd Edition. O'Reilly Media. Chapter 1, "Introduction," describes the Unix-like design of Linux, including its standard filesystem layout and core utilities inherited from Unix, such as the rm command.