APA (7th ed.) Citation

(1980). Directory information service. Nr. 1. Entries 5127 - 5644. A periodic supplement to the 1st ed. of the Directory of directories. Inf. Enterprises.

Chicago Style (17th ed.) Citation

Directory Information Service. Nr. 1. Entries 5127 - 5644. A Periodic Supplement to the 1st Ed. of the Directory of Directories. Detroit: Inf. Enterprises, 1980.

MLA (9th ed.) Citation

Directory Information Service. Nr. 1. Entries 5127 - 5644. A Periodic Supplement to the 1st Ed. of the Directory of Directories. Inf. Enterprises, 1980.