If you have no *.bib file, you can use a references field in the document’s YAML metadata. This should include an array of YAML-encoded references, for example:
---
title: "Writing an academic paper in R"
author: "Author"
date: "Date"
output:
pdf_document:
number_sections: yes
toc: yes
references:
- id: Meyer2000
title: A Constraint-Based Framework for Diagrammatic Reasoning
author:
- family: Meyer
given: Bernd
volume: 14
issue: 4
publisher: Applied Artificial Intelligence
page: 327-344
type: article-journal
issued:
year: 2000
---
# Introduction
`@Meyer2000` results in @Meyer2000.
`@Meyer2000 [p. 328]` results in @Meyer2000 [p. 328]
`[@Meyer2000]` results in [@Meyer2000]
`[-@Meyer2000]` results in [-@Meyer2000]
# Summary
# References
Rendering this file results in the same output as in example "Specifying a bibliography".