Samukkansika mode of preaching
A Lord Buddha doing two type of preach. One is a normal preach like in the Sutta Pitaka in Pali Canon. Other one is 'Samukkansika mode of preaching' extensively on 'Four Noble Truths' which preach with Lord Buddha's super-normal abilities.
When a Lord Buddha doing a Dharma preach, he start his preach with giving charity stories(Dāna katha), Morality stories(Sīla katha) etcetera. Then listeners minds getting calm and clear, now Lord Buddha enter to the 'Samukkansika mode of preaching'. This is a very long(containing many hundred thousand words) preach extensively on 'Four Noble Truths' do in high speed but every one can understand each word clearly. With this preach, many beings realize Nirvana but no one can't remember this preach. So, there are no book showing this preach. The easiest way to realize Nirvana is listening to the 'Samukkansika mode of preaching' of a Lord Buddha. Someone may attain Sotapanna, Sakadagami, Anāgāmi, or Arahat status. But still a being must have some kind of Pāramitā fulfilled in the past or previous lives otherwise he could not realize Nirvana. So, studying Dharma and Abhidhamma in this life may help to understand Nirvana from a future Buddha after very long time in the Samsara.
'The Four Noble Truths' by Ven. Professor Rerukane Chamdavimala Maha Nahimai