online catalogs of Russian collections

[gagarin]

I am looking for digital images of paintings from exhibition in Moscow 1892.  Can anyone recommend good online catalogs of art?   I am not having any luck with the normal search engines.

I am looking for the following paintings that were listed as  "Russian School":

1.  Боровиковскiй  "Поргп. Гр. Орловой-Денисовой"
2.  Ивановъ "Магдалина"

The scanned document is difficult to read. I am not sure if I have transcribed the spellings correctly.