[3] His study of Hindu texts and scholarship, while living with practicing Vaishnava Hindus there, resulted in his Der Hinduismus published in 1965.
[7] He has spent ten years in India and has researched primary sources in various languages, including Sanskrit, Hindi, Pali, Latin, Classical Greek, German, Italian and French.
[8] He is the author of 53 works in seven languages listed at worldCat[9] In a 1991 review of the 1st edition of Klostermaier's Survey of Hinduism (the book is now in its 3rd edition), Joel Brereton states that the book's "methodological eclecticism and emphasis on indigenous interpretation are reasonable strategies", but Klostermaier in his attempt to bring forward "Hindu voices to explain Hinduism, occasionally offers views that have little currency in modern scholarship".
Brereton adds, "the book has a number of unique virtues, includes recent developments in Hinduism, and shows an intimacy with Hindus and the present realities of Hindu life.
For instance, Klostermaier considers the Indus Valley civilization as Vedic-Indian, which pushes back the Vedic period by several thousand years beyond the accepted chronology.