Revākhaṇḍa of the Skandapurāṇa manuscripts (RKS) 103.9

103.9

rāvaṇasya sutaḥ saṃkhye hataś cākṣakumārakaḥ /
evaṃ rāmāyaṇe jāte sītā mokṣe kṛte tataḥ //

And Rāvaṇa's son, young Akṣa, was slain in battle. / When the events of the Rāmāyaṇa had thus taken place, and the liberation of Sītā was achieved,