Cyanotype powders...??

Hey, I am wondering if anyone is familiair with the following chemicals for the usage in the cyanotype process....??
Ammonium Iron (III) Citrate
and Potassium Hexacyanoferrate (III)
I ordered these powders several years ago and I can't find any recipe for it online....
Anyone...??? Greetings from the Netherlands.

they are more commonly known as ferric ammonium citrate and potassium ferricyanide.

the typical formula is equal quantities of each of approx 8% ferricyanide solution and 20% citrate solution, mixed together just before use.

but there are many variations, mostly rather minor.

a bit of Googling will find much more information for you

Thanks...!