Girls Und Panzer: Ribbon Warrior by Nogami Takeshi — Ongoing

P03

"Tankathlon is a new form of tank sport gaining slowly gaining popularity among Senshado enthusiasts. While also involving tank battles, Tankathlon is distinguished by its lack of official oversight allowing any school with tanks to participate in a battle anywhere at any time, and a 10-ton weight restriction on tanks used, limiting battles to light tanks and tankettes." –Manga Updates

For the main series, click here.
For "Little Army", click here.
For the "Motto Love Love" spin-off, click here.

Chapter 1 released Sep 17 '14
Chapter 2 released Oct 11 '14
Chapter 3 released Nov 15 '14
Chapter 4 released Dec 26 '14
Chapter 5 released Feb 22 '15
Chapter 6 released Mar 22 '15
Chapter 7 released Aug 4 '15
Chapter 8 released Aug 21 '15
Chapter 9 released Nov 20 '15
Chapter 10 released Feb 19 '16
Chapter 11 released Jul 15 '16
Chapter 12: Jajka's Battle 2 released Dec 30 '16
Chapter 13: Tategoto Highschool's Aung-san - Part 1 released Dec 30 '16
Chapter 14: Tategoto Highschool's Aung-san - Part 2 released Feb 23 '17
Chapter 15: Kuromorimine Strikes Back - Part 1 released Mar 6 '17
Chapter 16: Kuromorimine Strikes Back - Part 2 released Jun 16 '17
Chapter 17: Kuromorimine Strikes Back - Part 3 released Jun 25 '17
Chapter 18: Kuromorimine Strikes Back - Part 4 released Jul 25 '17
Chapter 19: Kuromorimine Strikes Back - Part 5 released Jul 29 '17
Chapter 20: Kuromorimine Strikes Back - Part 6 released Sep 19 '17
Chapter 21: Kuromorimine Strikes Back - Part 7 released Sep 19 '17
Chapter 22: Darjeeling's entry released Sep 19 '17
Chapter 23: To each their own emotions Part 1 released Sep 19 '17
Chapter 24: Uszka's Feelings released Oct 4 '17
Chapter 25: Introducing the tanks!! released Oct 4 '17
Chapter 26: Arisa and Yojimbos released Oct 9 '17
Chapter 27: Orange Pekoe's Battle released Oct 31 '17
Chapter 28: Aung-san vs Nishizumi Mask! released Oct 31 '17
Chapter 29: Akaboshi Koume, Tactician released Nov 12 '17
Chapter 30: Nishi and Mika released Nov 12 '17
Chapter 31: Nina and Alina struggle hard released Nov 12 '17