[Ger-Poland-Volhynia] Busenius or Buzenus

[B Hirsekorn]

I am trying to find birth records for my grandmother and
her siblings. Last name is Busenius (alternate spelling may be Buzenus or
something else) the date range is 1875 to 1898 in the Warsaw area.

The birth place given for the great-grandparents too vague
to be useful. 
Great-grandmother's maiden name too common to be useful.

There is nothing on http://www.geneszukacz.genealodzy.pl/ and the name doesn't appear on any websites checked. Other than the images on http://szukajwarchiwach.pl/being
too small to be readable, 1875 to 1898 seem to be missing. 


Are any Warsaw records for these dates?
Note: This family was not in Volhynia.

Betty