Sparring - dialogue and help  - Arnold Sorensen  - USA

and

Victor Engstrom, Danish West Indies Mail 1754-1917 

KPK´s Bibliotek - Nordisk Filatelistisk Tidsskrift 

Robert G Stone - "The mails by German Packets to and from St.Thomas, DWI"

The bisected 4 cents stamp by Torben Hilberg.

Inga and Hans Mortensen  - photos of bisected

Frank Banke  - photos of bisected

Jan Læby - photos of bisected