@goodwolfWhat do you mean by 'formula'?
Toree's next card is an 'e' card, so
e1977 is correct.
Elle's next card is an 'f' card, so that would be f1553.
The 'f' cards always have xxx in the card pics; the 'e' cards never.
Maybe you mean the linkset.
If yes, then use this:
[linkset]f1630[/linkset] [linkset]e1980[/linkset]
That will show these cards: