Formula definitions for financial functions

Hi,

We're lacking formula definitions or references to algorithms how to
calculate for a bunch of financial functions.

In particular the functions are:

ACCRINT
ACCRINTM
COUPDAYBS
COUPDAYS
COUPDAYSNC
COUPNCD
COUPNUM
COUPPCD
FV
INTRATE
IPMT
IRR
ISPMT
ODDFPRICE
ODDFYIELD
ODDLPRICE
ODDLYIELD
PPMT
PRICEDISC
PRICEMAT
SSL
SYD
TBILLEQ
TBILLPRICE
TBILLYIELD
VDB
XIRR
XNPV
YIELD
YIELDDISC
YIELDMAT

Could anyone come up with some of those?

Thanks
  Eike

-- 
Automatic string conversions considered dangerous. They are the GOTO statements
of spreadsheets.  --Robert Weir on the OpenDocument formula subcommittee's list.