Attack on Titan: The Essential Manga Chapters Anime-Only Fans

There's not much discrepancy between Attack on Titan's manga and anime but certain chapters of the manga come highly recommended.

Is the Ending for the 'Attack on Titan' Anime Different From the Manga?

Watch Attack on Titan - Crunchyroll

Attack on Titan: The Essential Manga Chapters Anime-Only Fans Should Read

Best Episodes of 'Attack on Titan' to Rewatch

The fascist subtext of Attack on Titan can't go overlooked - Polygon

Attack on Titan Cliffhanger Teases a Major Farewell

Attack on Titan recap: the entire story so far before Final Season Part 3 - Meristation

Attack on Titan Colossal Edition

About Chapter 139 and the ending of Attack on Titan as an Anime-Only (Mild Spoilers as they are out of context) : r/ShingekiNoKyojin