From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - August 11, 1898
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - February 16, 1900
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - February 21, 1900
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - February 25, 1900
From Isidore Guerin to Sr Francoise-Therese (Leonie) - March 9, 1900
From Isidore Guerin to the Carmel of Lisieux – Easter 1900 [ April 15]
From Isidore Guerin to Sr Marie of the Sacred Heart – June 21, 1900
From Isidore Guerin to Sr Francoise-Therese (Leonie) - June 30, 1900
From Isidore Guerin to Sr Francoise-Therese (Leonie) - July 8, 1900
From Isidore Guerin to Sr Francoise-Therese (Leonie) - December 30, 1900
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - February 4, 1901
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - February 13, 1901
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - March 11, 1901
From Isidore Guerin to Mother Marie de Gonzague – September 11, 1901
From Isidore Guerin to Sr Francoise-Therese (Leonie) - January 3, 1902
From Isidore Guerin to the Mother Prioress and Sisters –1903
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - February 12, 1904
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - May 6, 1904
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - July 19, 1904
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - September 16, 1904
From Isidore Guerin to Mother Agnes Agnes of Jesus - 1904
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - January 1905
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - January 14, 1905 (?)
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - January 16, 1905
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - March 25, 1905
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - April 4, 1905
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - April 14, 1905
From Isidore Guerin to her daugther to Marie Guerin (sr Marie of the Eucharist) - April 14, 1905 (2nd letter)
From Isidore Guerin to Mother Agnes of Jesus – June 1905
From Isidore Guerin to his nieces – April 4, 1906
From Isidore Guerin to his nieces – December 22, 1907
From Isidore Guerin to Sr Francoise-Therese (Leonie) - 1907?
From Isidore Guerin to his nieces – February 27, 1909
From Isidore Guerin to Mother Agnes of Jesus – March 10-22, 1909