Just a remark to the Org-Mode Reference Card (http://orgmode.org/orgcard.pdf).

There is a little bug in the spreadsheet description.

wrong:
sum from 2nd to 3rd hline |:=vsum(@II..@III)|

correct:
sum from 2nd to 3rd hline |:=vsum(@II..III)|

The second at symbol must be deleted for correct working.

Regards,
-frank