Don't worry, neither Airbus that demands full back stick nor Boeing that asks for pull-up-until-stickshaker during GPWS escape maneuvers are wrong. Both techniques get you very near Vx.
Best L/D ratio (ie BEST ANGLE of Climb Vx)
...is very common misconception, stemming from mixing up power and thrust. Thrust for turbojets is fairly constant over the speed range, while for propeller aeroplanes, power is more-or-less constant, while the trust diminishes with speed. Power is thrust multiplied by speed, regardless of the propulsion. Vx is speed at which there is greatest thrust excess, while Vy is speed where there is the greatest power excess.
Setting the props (which, as we all know, are for boats) aside, the greatest excessive thrust for the jet is when the drag is minimal and that's below best L/D speed. Green dot will give you Vy, not Vx. Following approximations are good enough for everyday use:
Vx = min drag = maximum endurance
Vy = best L/D = maximum range