Reference:

Javier Esparza, Michael Luttenberger, and Maximilian Schlund. A brief history of Strahler numbers — with a preface. Technical report, Technical University of Munich, 2016.

Suggested BibTeX entry:

@techreport{EsparzaK16,
    author = {Javier Esparza and Michael Luttenberger and Maximilian Schlund},
    institution = {Technical University of Munich},
    title = {A Brief History of {S}trahler Numbers --- with a Preface},
    year = {2016}
}