The terms you use to find books and articles on LGBTQ2 will depend on the type of tool you're using, for example: Research Guides, OneSearch, or a specific database.
When you're using OneSearch you can use keywords such as: LGBTQ, lesbian, gay, bisexual, trans, queer or gay people.
You can also keyword search LC Subject Headings that have been used used to classify books by topic. These are some terms that are used for research focused on LGBTQ2: Queer theory, transgender people, gender identity, sexual minorities, gender-nonconforming people, gay and lesbian studies, two-spirit people, bisexuals, gay rights, and gay liberation movement.
If you're using a particular database, like Academic Search Complete, you can start with known keywords, like the ones listed above for OneSearch, but once you get your results, take a look at the specific subject terms assigned to that article. The subject terms used in Academic Search Complete, for example, include: LGBTQ people, sexual minorities, gender identity, LGBTQ communities, sexual orientation, LGBTQ rights and LGTBQ youth.