Appendix I Multiple References
Subsection I.1 Multiple Specialized References
You might want to have lists of references, in the back, but with multiple such lists. Make an <appendix> to hold them, give it some structure (for an <article>, a leading <subsection>, such as the one you are reading right now), then follow with multiple <references> divisions. A typical citation will then look like: [I.3.2].
References I.2 General References
[1]
Gilbert Strang, The Fundamental Theorem of Linear Algebra, The American Mathematical Monthly November 1993, 100 no. 9, 848–855.
References I.3 Specialized References
[1]
Gilbert Strang, The Fundamental Theorem of Linear Algebra, The American Mathematical Monthly November 1993, 100 no. 9, 848–855.
[2]
Gilbert Strang, The Fundamental Theorem of Linear Algebra, The American Mathematical Monthly November 1993, 100 no. 9, 848–855.