APA (7th ed.) Citation

Essen, A. v. d., & Levelt, A. H. M. (1980). Irregular singularities in several variables formal theory in the unmixed case.

Chicago Style (17th ed.) Citation

Essen, Arno van den, and Antonius Henricus Maria Levelt. Irregular Singularities in Several Variables Formal Theory in the Unmixed Case. Nijmegen, the Netherlands, 1980.

MLA (9th ed.) Citation

Essen, Arno van den, and Antonius Henricus Maria Levelt. Irregular Singularities in Several Variables Formal Theory in the Unmixed Case. 1980.

Warning: These citations may not always be 100% accurate.