I suggest doing a literature search for papers published that use those and see if the authors indicate where they obtained them (or if they made their own). For example, one paper lists Jiangsu Hecheng Advanced Materials as a supplier of HTD028-200.

Hello

I also agree with the opinion of Mr. John Francis Miller. But the following page also contain information about the sale of liquid crystals.

In my opinion, you should search them using CAS number.

https://www.ossila.com/collections/liquid-crystals

Phenyl 1-hydroxy-2-naphthoate

CAS 132-54-7

From €144

https://www.alibaba.com/product-detail/Australia-in-stock-colorless-liquid-Crystal_1600958675924.html

https://www.sigmaaldrich.com/US/en/products/materials-science/electronic-materials/liquid-crystals

https://www.tcichemicals.com/CA/en/product/index

https://www.merckgroup.com/en/expertise/displays/solutions/liquid-crystals.html

https://en.wikipedia.org/wiki/Liquid_crystal