Question About Russia

Can you post the front cover of the book you keep mentioning, please?

Informative images, thank you Vasia,
clears up any remaining curiosities.

It can be frustrating, I refer to modern Fiji, with supposedly 3 differing wmks, and other orientations.
I barely can identify perhaps 2 out of every 10 that have a visible wmk.

I know I'm supposed to stick to one stamp per thread
But I was wondering if it would be ok to post my question that I have in this one spot
This is a learning curve for me I'm really interested I know there's things I don't understand yet so
I don't want to flood the form with my randomness , I have lots of curiosity
I do appreciate all the help I've gotten here and don't want to seem like I'm not doing my own homework
But some stuff I come across I need a little help understanding
Would this be ok?

if I happen to come across something that my be of interest I could put it into a new thread

This is the book I purchased
Sorry I just seen the post asking for the cover

Apologies if I should make a new post for this!
I came across a use and beat up 20 kop
Could be nothing damage or forgery but I think it's fun

At first I thought this my be a "no watermark letter and without line"variety
But under closer scrutiny could it be a "watermark with narrow spaced lines"
Or is that just glue? I don't have experience with this
I appreciate the help (again not sure if I am ok to post all my randomness here)
Apologies if I should be posting a new thread each time
And the double/triple posts I try not to

(Yes I know it's torn and has a nasty hinge so worthless to someone else :)




And just cause I'll add a photo from the post before this I forgot to add
I think it looks pretty sweet (facedown in fluid)