Satguru Sivaya Subramuniyaswam writes the following in his book Dancing with Siva, in what is I believe the glossary section:
Śaiva Agamas: The sectarian revealed scriptures of the Saivas. Strongly theistic, they identify Śiva as the Supreme Lord, immanent and transcendent. They are in two main divisions: the 64 Kashmir Saiva Agamas and the 28 Śaiva Siddhanta Agamas. The latter group is the fundamental sectarian scriptures of Śaiva Siddhanta. Of these, ten are of the Śivabheda division and are considered dualistic: 1) Kāmika, 2) Yogaja, 3) Chintya, 4) Kāraṇa, 5) Ajita, 6) Dīpta, 7) Sūkshma, 8) Sahasraka, 9) Amsumat and 10) Suprabheda. There are 18 in the Rudrabheda group, classed as dual-nondual: 11) Vijaya, 12) Niḥśvāsa, 13) Svāyambhuva, 14) Aṇala, 15) Vīra (Bhadra), 16) Raurava, 17) Makuta, 18) Vimala, 19) Chandrajñāna (or Chandrahāsa), 20) Mukhabimba (or Bimba), 21) Prodgītā (or Udgītā), 22) Lalita, 23) Siddha, 24) Santāna, 25) Sarvokta (Narasimha), 26) Paramesvara, 27) Kirana and 28) Vätula (or Parahita).
Rishi Tirumular, in his Tirumantiram, refers to 28 Āgamas and mentions nine by name. Eight of these Kāraṇa, Kāmika, Vīra, Chintya, Vätula, Vimala, Suprabheda and Makuta—are in the above list of 28 furnished by the French Institute of Indology, Pondicherry. The ninth, Kalottāra, is presently regarded as an Upagama, or secondary text, of Vätula. The Kamika is the Agama most widely followed in Tamil Śaiva temples, because of the availability of Aghorasiva's manual- commentary (paddhati) on it. Vīra Šaivites especially refer to the Vatula and Vīra Agamas. The Saiva Agama scriptures, above all else, are the connecting strand through all the schools of Saivism. The Agamas themselves express that they are entirely consistent with the teachings of the Veda, that they contain the essence of the Veda, and must be studied with the same high degree of devotion. See: Agamas, Vedas.
I know that original primary sources are preferred, but you said that Indologists/Orientalists would be okay. This is from a book written by a guru. I've chosen that citation because it's a fairly reliable source and it offers a bit more context. But the list can be found elsewhere, too:
The same list is also included in table form here in the Śivajñāna Siddhiyār by Arunandi Śivāchārya. It's also here, here, and here.
Hope that this helps!