How should I cite a labor union CBA in Turabian style?

Question

I need to cite a Collective Bargaining Agreement (CBA) negotiated between a labor union (United Food and Commercial Workers Union Local 555) and an employer (Fred Meyer Stores, Inc., a subsidiary of Kroger). How would I do this? I am using Turabian notes style.

The best I've come up with is this:

Fred Meyer Grocery Contract, Coos & Western Douglas Counties & Brookings, Oregon. Tigard, OR: UFCW Local 555, 2022.

That takes it as a book with no named author, published by the union. It takes it as the first edition, even though there have been revisions, because it is the first under this title; the most recent change was for the purpose of including workers in Brookings, Oregon in the bargaining unit.

Should I list the union and employer as co-authors?

Front cover

[UFCW Local 555 logo]

Fred Meyer
Grocery Contract

Coos & Western Douglas Counties
& Brookings, Oregon
FI05FO

Effective
November 6, 2022 - November 5, 2025
Updated to reflect 2023 state wage increase

www.ufcw555.org

Title page

FRED MEYER STORES, INC.
COOS AND WESTERN DOUGLAS COUNTIES AND BROOKINGS, OREGON
GROCERY, BAKERY, AND NON-FOODS CLERKS AGREEMENT
WITH
UNITED FOOD & COMMERCIAL WORKERS UNION LOCAL 555

November 6, 2022 through November 8, 2025

[table of contents ommitted]

Contract Ratified December 30, 2021
Language Changes Effective November 6, 2022
Brookings, Oregon Effective October 23, 2022
Unless Otherwise Specified

Page footer

This footer is found on each page after the title page.

FRED MEYER STORES, INC. and UFCW 555
Coos and Western Douglas Counties and Brookings, OR
Grocery, Bakery, and Non-Foods Clerks
November 6, 2022-November 8, 2025

Back cover

[statement about Weingarten Rights]

UFCW LOCAL 555
7095 SW Sandburg St.
Tigard, OR 97223
503-684-2822

[UFCW 555 union label]

Answer 1

I found a source explaining how to cite CBAs in APA style, and it recommends including essentially the same information I had, but also listing the union and employer as authors. I changed my citation to this; I called my professor to check, and he agreed that it's OK.

UFCW Local 555 and Fred Meyer Stores. Fred Meyer Grocery Contract, Coos & Western Douglas Counties & Brookings, Oregon. Tigard, OR: UFCW Local 555, 2022.