Two early works by Sadashiv Ambadas Dange and Richard F. Gombrich, respectively, remain excellent resources for Vedic ritual cosmology. See Dange's "Cosmo-Sexualism in the Vedic Ritual," in Charudeva Shastri Felicitation Volume, edited by Suniti Kumar Chatterji, Triloki Nath, Satya Vrat, and Dharmendra Kumar Gupta (Delhi, 1974), pp. 23–44; and Gombrich's "Ancient Indian Cosmology," in Ancient Cosmologies, edited by Carmen Blacker and Michael Loewe (London, 1975), pp. 110–142. M. A. Mehendale's short "Sapta Devalokāh," in Charudeva Shastri Felicitation Volume, edited by Suniti Kumar Chatterji, Triloki Nath, Satya Vrat, and Dharmendra Kumar Gupta (Delhi, 1974), also gives a good basic introduction to the idea of the seven worlds. For more detailed, thematic studies of Vedic cosmology, see Marius Schneider's "Das Schöpfungswort in der vedischen Kosmologie," in Musicae Scientiae Collectanea: Festschrift Karl Gustav Fellerer zum 70. Geburtstag, edited by Heinrich Hüschen (Cologne, Germany, 1973), pp. 523–526, and his "Die Grundlagen der Kultsprache in der vedischen Kosmologie," in Sprache und Sprachverständnis in religiöser Rede: Zum Verhältnis von Theologie und Linguistik, edited by Thomas Michels and Ansgar Paus (Salzburg, Austria, 1973), pp. 13–60. Albrecht Wezler's "Thin, Thinner, Thinnest: Some Remarks on Jaiminīya Brāhmana 1:144," in India and Beyond: Aspects of Literature, Meaning, Ritual, and Thought: Essays in Honour of Frits Staal, edited by Dick Van Der Meij (Leiden, 1997), pp. 636–650, engages the important question of worldview in the Brāhmaṇa literature. Henk W. Bodewitz gives a good sense of how early Vedic themes might give rise to later Purāṇic ones in "Pits, Pitfalls, and the Underworld in the Veda," Indo-Iranian Journal 42, no. 3 (July 1999): 211–226. Moving forward to the Upaniṣads, Joel P. Brereton's excellent "Cosmographic Images in the Brhadāranyaka Upaniṣad," Indo-Iranian Journal 34 (1991): 1–17, gives a good specific case study of a single Upaniṣad that can be used as a launching point for the study of other Upaniṣads. For another integrative view of earlier and later texts, see Petteri Koskikallio's "When Time Turns: Yugas, Ideologies, Sacrifices," in Studia Orientalia 73, edited by Palva Heikki, Tapani Harviainen, Asko Parpola, and Harry Halén (Helsinki, Finland, 1994), pp. 253–271.