A journal article is a short document which reports the results of a research project such a laboratory experiment, field trial, case study or any set of circumstances designed to test a hypothesis.
1) Journal articles in the sciences generally follow
a specified format which divides the article into several sections:
2) Journal articles will also list the author(s) of the article and their affiliation. These affiliations should indicate an academic or governmental role, which can connote expertise. Commercial or other affiliations can indicate a possible source of author bias.
3) Journal articles should also include citations in the text which correspond to references listed at the end of the article. Many different citation styles exist and vary by journal and discipline, but some type of citation should be present to indicate sources of information used to build or frame the research.
4) Journal articles often use technical language and scientific names, as they are produced for other topic experts. Journal articles may be difficult for a non-expert to fully understand.
5) Lastly, many journal articles provide documentation of the peer-review process, indicating that multiple experts have reviewed the content of the document to ensure quality. If not included in the text of the article, peer-review policies may be found linked from journal home pages.
Books are longer works comprised of many chapters, part or sections, intended to cover a topic comprehensively. Generally a table of contents is provided and allows the reader to quickly scan the contents of the book. Most books are assigned an International Standard Book Number (ISBN), which may be used to differentiate and locate specific titles, editions and formats. Several different types of books help meet information needs.
Monographs cover a single topic, and in the sciences are often produced by teams of experts.
Textbooks are often similar in format to monographs, but provide instruction on core concepts and principles in a disciplinary area. Textbooks often include illustrations, diagrams, charts or other visual information to help students understand concepts. Textbooks generally include reflection questions or problem sets at the end of each section or chapter to prompt student review of content covered.
Reference books differ from a standard monograph in that they are designed to provide shorter, distinct pieces content or data. Each piece of content (often referred to as an entry) may be read separately from every other piece of content, although content may be related or linked.
Reference books can be a good source of background information about a topic and often can refer the reader to more complete works to continue their research. Common types of reference books include Encyclopedias, Dictionaries, and Indexes, although many types exist. Most reference books are now available in electronic format and may consist of a series of linked web pages or database records.
Trade magazines or journals generally represent an organization or commodity group within industry and are produced for a practitioner audience (i.e., farmers, dietitians, veterinarians, etc.). 
Trade articles can be good sources of background information or cover current issues which have not yet been analyzed by academic research.
Trade articles have several main differences from journal articles:
Extension publications consist of documents and other sources of information created by the Cooperative Extension Service of a Land Grant university. The Cooperative Extension Service (sometimes shortened to Extension Service or just Extension) is a partnership between Federal, State, and/or local governments and a Land Grant academic institution to provide technical assistance, information and other support to citizens on food, agriculture, environmental and related issues (business planning, finance, etc.).
Extension publications often translate peer-reviewed research and other information on a topic for general audience. Extension publications range from short fact sheets, to longer handbooks or manuals, but tend to provide simple summaries and many figures, illustrations, images, reference tables and other non-text content. You can review University of Maryland Extension publications at https://extension.umd.edu/learn/publications
Government documents are easily identified by the publisher. The U.S. Government Printing Office (commonly abbreviated as GPO) is the main publisher of U.S. government documents, but agencies may self publish documents. Many government documents are numbered as parts of series, or dated by release date to aid in identification. Contents vary from reports and technical overviews to transcripts to laws and regulations. Sometimes data, especially historical data, has been published in tables in print documents rather than as electronic files.
Conference proceedings result from conferences, symposia, and other meetings of scientific, governmental, or academic organizations about a specific topic. Proceedings can be identified by the wording of the title and a place and date, often part of the title or provided on the cover and/or title page. The table of contents may be organized to reflect the schedule of the meeting.
Speakers are often experts on the topic, but are likely to represent all parts of industry including academia, government, non-profit organizations, commercial businesses, and other stakeholders related to the event topic.
Proceedings may consist of papers based on content presented at the meeting or the actual conference presentation or program materials (transcript, slides, summaries, abstracts). Some conference presentations are refereed or peer-reviewed before presentation or publication. The call for presentations/proposals or publishing organization website may need to be consulted to determine if the proceedings have be reviewed. As conferences may be an opportunity to present preliminary or ongoing research, as well as, anecdotal information, not all conference presentations will be reviewed. As a result, citations to conference proceeding information may need to be supported with other sources of information.
