Bibliography reference aka 2 Ways Anchor

Hi.

Lets say I have a quote:

a) "If you want to live a happy life, tie it to a goal, not to people or things." (1)

and on the bottom of the page i have (without b)):

b) (1) – Albert Einstein

When I click (1) from (a) it goes to (1) from (b) -> Here i can use Anchor

But I want: When i click (1) from (b) - To go to (1) from (a) like a 2 way Anchor. I dont know how can i do this?

Like the reference from 1 to go both way: from 1-a to 1-b and from 1-b to 1-a

It is not important to use only anchor, but i want a simple way to achieve what i wrote above.

Can you help?

Thanks!