This article provides an extensive literature review on Negotiation definitions. The aim was to broaden the current epistemology on the field of research. The subject has also attracted increasing scholar attention over the past 40 years. Despite the tremendous technological advancements regarding the internet era, researchers still face ink-and-paper-format challenges when gathering direct quotations. In some cases, most prominent and cited research is charged. Many researchers are limited to the digital libraries subscribed by their educational institutions. Therefore, this research will be beneficial to scholars, and practitioners in general, because it gathers in a single study the most critical direct quotations on Negotiation definitions within the past few decades. Key findings pointed to common factors such as people, process, and substance within the N=30 quotes investigated. Some of the quotes were available online, scanned as pictures - without the possibility of word search; the oldest ones were retrieved exclusively from the ink-and-paper format. Both cases were the hardest to retrieve. Resulting citations were compared and investigated through content analysis. Finally, discussion and future research compile the present work.