What is the earliest evidence for the existence of superfluidity in neutron stars?

I'm about to present the subject in a seminar and I'm under the impression that at the moment there is no conclusive evidence the superfluidity actually exists in neutron stars (although it is widely believed to be so?).

I've found this review but it doesn't seem to be very conclusive.

What is the earliest evidence for the existence of superfluidity in neutron stars?

I'm about to present the subject in a seminar and I'm under the impression that at the moment there is no conclusive evidence the superfluidity actually exists in neutron stars (although it is widely believed to be so?).

I've found this review by Chamel (2017), but it doesn't seem to be very conclusive.

What is the earliest evidence for the existence of superfluidity in neutron stars?

I'm about to present the subject in a seminar and I'm under the impression that at the moment there is no conclusive evidence the superfluidity actually exists in neutron stars (although it is widely believed to be so?).

What is the earliest evidence for the existence of superfluidity in neutron stars?

I'm about to present the subject in a seminar and I'm under the impression that at the moment there is no conclusive evidence the superfluidity actually exists in neutron stars (although it is widely believed to be so?).

I've found this review but it doesn't seem to be very conclusive.