I find that the periodic tables in general chemistry textbooks are not consistent.  In some textbooks, Ce is the first lanthanide and ends with Lu.  In other texts, I see that La is the first lanthanide & ends with Yb.  I would argue the format should be the former since Lu3+ is a f14 element.  I'm sure there are papers on this topic, but it still drives me nuts that elements can be placed in different positions.  What are your thoughts?