In a village I found in desert, all villagers died, except the Librarian. I cured a Zombie Villager, that turned out to be another Librarian. 

As [the wiki](http://minecraft.gamepedia.com/Villager#Willingness) describes:

> 
> *Additionally, villagers must be "willing" in order to breed. After
>  mating, they will no longer be willing, and must be made willing
>  again.*
> 
> 
> *Villagers may become willing when the player trades with them.
>  Willingness is granted the first time a new offer is traded, or at a
>  one-in-five chance on subsequent trades. Green particles will appear
>  if the villager becomes willing by trading. This will not cause them
>  to immediately seek out a mate, however.*
> 
> 
> *Villagers can also become willing by having either 3 bread, 12 carrots
>  or 12 potatoes in one stack in their inventory. Any villager with an
>  excess of food (usually farmers) will throw food to other villagers,
>  allowing them to pick it up and obtain enough food to become willing.
>  You can also throw bread, carrots, or potatoes at the villagers
>  yourself to encourage breeding. Villagers will consume the required
>  food upon becoming willing.*
> 
> 
> 

I have traded with them until they don't want paper anymore, so I traded for the enchanted books, then traded with paper again. I gave them lots of bread, potatoes and carrots. None of them shows hearts, and I ran low on Emeralds, as I had traded them for enchanted books. 

I'm planning to cure one more villager. I have searched how to breed and most tutorial uses the example of the Farmer. I can't find any mechanics that list needing a Farmer.

**Is a Farmer villager required to breed?**  

If it is, do I need both Farmers to breed, or just one of them?  

If it's not, is there any chance for my two Librarians breeding?  

*Are there new mechanics on the latest 1.8.7 version of Minecraft?*