Projectivities of free products
Rendiconti del Seminario Matematico della Università di Padova, Tome 42 (1969), pp. 341-387. 
@article{RSMUP_1969__42__341_0,
     author = {Holmes, Charles S.},
     title = {Projectivities of free products},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {341--387},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {42},
     year = {1969},
     mrnumber = {268286},
     zbl = {0245.20031},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1969__42__341_0/}
}
TY  - JOUR
AU  - Holmes, Charles S.
TI  - Projectivities of free products
JO  - Rendiconti del Seminario Matematico della Università di Padova
PY  - 1969
SP  - 341
EP  - 387
VL  - 42
PB  - Seminario Matematico of the University of Padua
UR  - http://www.numdam.org/item/RSMUP_1969__42__341_0/
LA  - en
ID  - RSMUP_1969__42__341_0
ER  - 
%0 Journal Article
%A Holmes, Charles S.
%T Projectivities of free products
%J Rendiconti del Seminario Matematico della Università di Padova
%D 1969
%P 341-387
%V 42
%I Seminario Matematico of the University of Padua
%U http://www.numdam.org/item/RSMUP_1969__42__341_0/
%G en
%F RSMUP_1969__42__341_0
Holmes, Charles S. Projectivities of free products. Rendiconti del Seminario Matematico della Università di Padova, Tome 42 (1969), pp. 341-387. http://www.numdam.org/item/RSMUP_1969__42__341_0/

[1] Baer, A.: The significance of the system of subgroups for the structure of the group, American Journal of Mathematics, 61 (1939) 1-44. | JFM

[2] Kurosh, A.: The Theory of Groups, Vols. I and II, Chelsea, New York, 1960. | MR

[3] Sadovsky, E.L. (ALSO SADOVSKI, SADOVSKII): a) Structural isomorphisms of free groups and free products, Mat. Sbornik 14 (56) (1944) 145-173. b) On structural isomorphism of free products of groups, Mat. Sbornik 21 (63) (1947), 63-82. | MR

[4] Suzuki, M.: Structure of a Group and the Structure of its Lattice of Subgroups, Springer Verlag, Berlin, 1956. | MR | Zbl