quadrature ring oscillator 5GHz

Hello,
I would like to design a quadrature ring oscillator at 5GHz.. Could someone suggest me which topology will be a good starting point? and some interesting papers that I could read for better understanding

Thanks in advance!

Easiest way to a quadrature oscillator is 4 stages of fully
differential gain, with three of them cross-connected (so
as to be inverting) and one straight (noninverting).

But you need to think about what you want besides
5GHz small signal oscillation. Presumably these quadrature
clocks have a purpose and that purpose wants "stuff" -
like drive strength, amplitude / logic levels, phase accuracy....

If you have to get to bang-bang square-looking CMOS
logic clock field, that needs downstream gain and some
efforts to make switching symmetric (5GHz out of a logic
inverter, with symmetric rise / fall times which consume
each 10% or less of the period, wants a pretty short gate
length and it's all going to go to hell if you have to throw
those signals across random routed logic for a millimeter,
etc.).

General purpose is probably not where this is headed, but
whatever the purpose wants, you need to make clear if
you want to get there by other than "random walk".