Looking for an online resource and/or disambiguation for the following reference on Pythagorean triples:
B. Berggren, Pytagoreiska trianglar, Tidskrift f¨or Element¨ar Matematik, Fysik och Kemi 17 (1934), 129–139
Online search on https://scholar.google.com yielded a number of citations, but no links to original paper. Any pointers/help is appreciated.
This was prompted by the following ambiguious mentions: (Emphasis added)
Keith Conrad, in this paper (https://kconrad.math.uconn.edu/blurbs/linmultialg/descentPythag.pdf) mentions:
In 1934, Berggren [3] showed every primitive Pythagorean triple $(a, b, c)$ with $b$ even can be generated from the triple $(3, 4, 5)$ by a $3$-fold ascent using the three matrices...
Wikipedia (as on Sep 29, 2022) states the following on the Pythagorean Triples article
By a result of Berggren (1934), all primitive Pythagorean triples can be generated from the $(3, 4, 5)$ triangle by using the three linear transformations $T1, T2, T3$ below, where $a, b, c$ are sides of a triple:...
My understanding is that both Conrad's paper and the Wikipedia article are describing the same process of generating primitive triples.
Is the result true for all primitive Pythagorean triples or only primitive Pythagorean triples with even $b$?