Anyone knows any reference or paper for the Full likelihood of proportional hazards model

[Tommy129]

 I am reading the Model and Likelihood of ICPHREG Procedure, I’m wondering that if there are any reference or paper for the following formula (full likelihood of proportional hazards model)? 

[Reeza]

Have you checked the ones listed in the Reference section?

https://documentation.sas.com/doc/en/statcdc/14.2/statug/statug_icphreg_references.htm

[pink_poodle]

In the references from @Reeza, probably third one from the top:
Cai, T., and Betensky, R. A. (2003). “Hazard Regression for Interval-Censored Data with Penalized Spline.” Biometrics 59:570–579. http://dx.doi.org/10.1111/1541-0420.00067.