I came up with following questions, while reading Wielandt's paper "Ein Beweis für die Existenz der Sylowgruppen". (I know the ideas of the proof, but my questions are related to some statements or comments in the original paper.) He starts with
In nicht wenigen Lehrbüchern der Algebra fehlt der Satz von SYLOW [= In not a few textbooks on Algebra, the Theorem of Sylow is missing (absent)].
Q.1 This paper is published in 1959. So, is it true that the Theorem of Sylow was absent in many algebra texts? (i.e. what are the popular algebra texts (before 1959) which do not mention this theorem?)
Q.2 In the proof, he says, let $|G|=p^{\alpha}r$. Let $\mathfrak{K}_1,\cdots, \mathfrak{K}_N$ be subsets (complexes) of $G$ of size $p^a$. I didn't understand the following statement.
Die Anzahl $N$ dieser „Komplexe“ $\mathfrak{K}_i$ ist nicht durch $p^{\varrho+1}$ teilbar, wenn $p^{\varrho}$ die höchste in $r$ aufgehende Potenz von $p$ bezeichnet;
Q.3 Finally, I couldn't understand his last suggestion:
Ähnlich ist schon Sylow selbst 1872 vorgegangen; eine kurze Durchführung findet man im Lehrbuch der Gruppentheorie von ZASSENHAUS, 1937, S. 100--101.
It would be grateful if one helps me to understand these statements.
In Q.1, I think "Algebra texts" means "abstract algebra texts", but not the school algebra; in other words, the texts would be introducing Groups, Subgroups, Lagranges theorem; but missing Sylow theorem.