How do I work on multiple pdf documents simultaneously

[Tsitso5C52]

How do I open and work on multiple documents simultaneously? An example would be, filling a form while a book is still open in the background. Thanks in advance for your assistance 

[Bernd Alheit]

Open the form in Acrobat Reader and the book in a browser.

[Tsitso5C52]

1. Thanks Bernd. Is there no way that I can have both of them on Adobe acrobat reader?  That is what I sought guidance on 

[Bernd Alheit]

Not possible with Acrobat Reader on Android or iOS. Possible with Acrobat Reader on Windows or Mac.