Mapping EOL species with GBIF species

I develop an application which is using data as a source of data for my own database. Also, we highly use GBIF data. I wonder if there is an unambiguous way to determine mapping EOL species with the GBIF counterparts. Like View this species on GBIF on EOL species pages.
If there is no such reference in opendata datasets, maybe it is possible to get GBIF taxonID/nubkey using EOL API?

I am so sorry, @margorski ! My notifications of forum activity seem not to have been working reliably for a couple of months. There is a taxon mapping between EOL and all major classifications that we use. The file is stashed in this opendata page. Unambiguous may be overstating it- that is the mapping our code has determined when attempting to match taxa between the databases. But we get good ancestry data from GBIF so the mapping should be reliable.