“strona umowy”

How do you translate “strona umowy” into English?
the only correct version:

“the party TO the agreement”

the party of the agreement
the side of the agreement
the part of the agreement

Now, your turn:

strona sporu - the party the dispute
strona negocjacji - the party negotiations
strona rozmów handlowych - the party trade talks
strona traktatu - the party the treaty
strona porozumienia - the party the settlement