Many are hunting in other coutries about coin variety.

http://en.wikipedia.org/wiki/Philippine_peso_coins

From post WWII to 1995 what are the metal composition of Philippines coin.

Who is the leading numismatic author or writer in Philippine coin?

As posted in wikipedia there is a transition of metal in 1 peso coin any chances that a cooper nickel existed pass in circulation reported or existed after its production stop.

What is the official year that cooper nickel peso stop production?

The latest updated book for US Philippine coins was authored by Lyman Allen. His last edition was in 2008. That was also his last since he sold his publication rights to another person because he close his coin shop and didn't wish to update anymore.
Currently, reknown U.S. collector and dealer Ken Seymore and Ray Czahor are the leading numismatist specializing in U.S. varities and errors but they never tried to published any books.
EWY

Thanks for the reply embosed.

Same thing have to look for reference written by other author who wrote it first.

Will just wait and see to all variety hunters both notes and coins both used in circulation and those that are already been pulled out if they have a news or new find.

Just for comparison to other countries.

http://userwebs.psknet.com/tbirde/tbirde1/Varieties/Varieties.html