It isn't new, but this one is my favorite, because of the Kerbin return phase angles (credits are on the map) : r/KerbalAcademy
KSP Tools
KSP Tools
How are you meant to figure out transfer windows in stock? - KSP1 Gameplay Questions and Tutorials - Kerbal Space Program Forums
How to Calculate Interplanetary Transfer Angles | KSP Let's Do The Math - YouTube
Orbit phasing - Wikipedia
Interplanetary Transfer Phasing — Orbital Mechanics & Astrodynamics
How to calculate the right angle for a Mun transfer in Kerbal Space Program - Quora
How to Calculate Interplanetary Transfer Angles | KSP Let's Do The Math - YouTube
KSP - How to land at Kerbal Space Center - (Math + Phase Angles) - YouTube
Comet Intercept Tutorial - KSP1 Tutorials - Kerbal Space Program Forums
Added phase angles for transfers to the Community Delta-V Map : r/KerbalSpaceProgram
KSP Planetary Transfer Quick Reference Chart: >>> Now Combined! <<< - KSP Fan Works - Kerbal Space Program Forums
Transfer Window Calculator | KSP 1.4.5 | Kordite | Flickr
GitHub - ABritInSpace/TransferCalculator-KSP2: An in-game interplanetary transfer calculator for KSP 2, including dV estimates and current/desired phase angles.
How to calculate a rendezvous?? - Science & Spaceflight - Kerbal Space Program Forums
Phase Angle
Basics of Space Flight: Orbital Mechanics
GitHub - agne16/KSP-Calculator: Companion app written for iOS to aid players of Kerbal Space Program to easily calculate Hohmann transfer orbits