I am wandering around Washington, D.C, paying closely attention to where I am, thinking about this riddle I am trying to solve. But nothing is gonna hit me.
I have a paper in my hands on which I wrote the following
LA Building, Hermes
LAC Bldg A, Hermegs
Can anyone help me to identify this building? I must find and use his door!
Suddenly my phone rings. Its M Oehm. He tells me to go back to the Library. He sounds very excited.
M Oehm: "Perhaps here? The rooms of the building in question have the right letter code."
He found out, that John Adams Building, the name of the LoC building, is abbreviated with LA, maybe LA5 points us to the fifth floor of the library. And even better, Hermes is there.
I hung up and started running back to the library.
At the west entrance from 2nd Street I finally found it. The Hermes-Door.
The first line on my paper was correct: LA Building, Hermes.
For those interested what I wrote on my paper:
Washington, D.C, at Independence Avenue between First and Second Streets, SE is the Library of Congress
The numbers given are valid ISSN Numbers, searchable at the LoC Website.
The found records have a blast of informations, I chose the Library of Congress Call Number
ISSN Number Call Number
Now, only taking letters into account that gives
LA5BL1DG11HE1RM1E839S1 -> LABLDGHERMES -> LA Building, Hermes
or with Sub-Item-Number
LAC5C64Bl1DG11A57HE1RM1E839G37S1 -> LACBLDGAHERMEGS -> LAC Bldg A, Hermegs
Note: All entries are classified as periodic or newspaper ("a periodic message")
Maybe this leads to an answer? Maybe I'm stuck wandering around in Washington, D.C.
Finally, there is a happy end.
Thanks to M Oehm for "calling" me, I would never have looked there.