Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Diatom:

"

Diatoms build intricate hard but porous cell walls called frustules composed primarily of silica.[4]:25–30 This siliceous wall[5] can be highly patterned with a variety of pores, ribs, minute spines, marginal ridges and elevations; all of which can be used to delineate genera and species.