Subject: Which is the 1st Lanthanide--Lanthanum or Cerium?

I am a HS chemistry teacher.  when I first started teaching, the 
first Lanthanide was Lanthanum.  Then Lanthanum was put into the 
transition block and the 14 Lanthanides are now seemingly 
considered to be Cerium through Lawrencium.  But modern books 
still differ on this in how they show the Periodic Table. Some 
show La in the body of the chart in with the Transition metals 
(and Ce as the 1st Lanthanide) and others show La as the first 
member of the Lanthanide series with Lr in with the 
Transitions.  I know that La is shown to have a d1 configuration 
with Ce configuration being d1 f1.But different books still show 
different placements.  Has IUPAC ruled on which is considered to 
be the first Lanthanide,  La or Ce?  which do books seem not to 
agree?  And if Cerium is the first Rare Earth then why not 
change the name of the series to the Ceride series instead of 
the Lanthanide Series?

Re: Which is the 1st Lanthanide--Lanthanum or Cerium?