More than 30 years searching a song
 

Yes. So is!

It is a song similar to "Just the way you are" and "Can't get enough of your love, babe" both of Barry White.

An entry with a deep voice (almost identical to "Can't get enough of your love, babe") and then a ballad R & B / Soul.

I've listened to all the songs of Barry White but I can not find it.

Could you please help me with songs with this format of artists similar to Barry White?

Thank you

Isaac Hayes maybe?

Isaac Hayes - I Never Can Say Goodbye

Teddy Pendergrass - Close The Door
I'm a newbie so can't post a link to YouTube yet - but look it up.
I'm almost certain this is the song you are describing - you could easily be forgiven for thinking that you were listening to Barry White when you hear this.
Pendergrass was also a master of the sweet seductive Philly soul song like Barry White; he had powerful gravelly baritone voice (though not quite as deep as White).
The track topped the US R&B Chart and sold over a million in the States. Sadly, it didn't register in the UK and I think that this why it has eluded you for so long.

Maybe Kiss - I was made for loving you