[Ger-Poland-Volhynia] Jeschke in Przedecz

[Marcus Klutzny]

Hi
In my case I4m looking for information about Hermann Jeschke born 
13.02.1888 in Przedecz (Lutheran christ).
His father was Karl Jeschke born about 1845 and mother was Emilie Dede 
born about 1852; both in Przedecz.
Hermann had some childrens ( most of them died) with his wife Alwine 
Schulz in this town.( He was married with her in age of 17!)
One of them was Oskar Jeschke. I found his datas of death from the WaST. 
He died 21.03.1944 in WWII in Monte Cassino.
He was born 21.03.1923 in Przedecz too.
That4s my clues for my research, but in this case many different 
timelines makes it difficult for me.
Now my Questions: In which churchbooks there are clues for my ancestors? 
Where ( for the different times) are these churchbooks or microfilms?
How can I found the other children of my grandfather?

Thanks in Advance for all ideas
Marcus Klutzny