The last step is to think about the sources which you will use for searching. There are three options:
An easily accessible source containing information of varying quality. If you search for scientific information, we recommend using specialist search engines for scientific texts such as Google Scholar (https://scholar.google.com) instead of the classic Google search engine, which like Yahoo, Bing etc. finds both high- and poor-quality websites (e.g. websites created by the lay public or for commercial purposes only).
Google Scholar uses a somewhat different searching mechanism: you do not need to write the AND operator, and a dash is used instead of the NOT operator. The asterisk (*) replaces not just characters in a word but a whole word. As far as individual grammatical variants are concerned, Google Scholar is able to derive them from the word entered and search for them on its own.
Library catalogues are also commonly accessible. We recommend using university catalogues or catalogues of libraries which operate on the national level (in Czechia there are National Library in Prague, Moravian Library in Brno). University libraries focus primarily on academic literature and national libraries archive all books and journals published in the Czech Republic thanks to the so-called legal deposit. If you cannot find the document in your library, you can contact the library with a request for an interlibrary loan (ILL).
Licensed online databases of academic literature are clearly a source of high-quality information, they always contain bibliographic data and sometimes even full texts of scientific articles or monographs. Most such databases contain information on publications whose quality is ensured by peer review, i.e. articles are only published when they passed review.
For searching, use first the Discovery service (http://discovery.muni.cz), which provides one interface for accessing records from almost all databases Masaryk University subscribes to. A part of this service is LinkSource which makes it possible to verify whether a full text is accessible (for more see the animated tutorial).
The same query is then used in Web of Science and Scopus databases, which are citation databases containing records from prestigious, academic and peer-reviewed publications. These publications are followed for their citation rate, i.e. how often other authors whose publications are in these databases cited them. The databases above do not store full texts, but they provide a linking service for each record which helps to verify whether the full text is available in another database (this feature can be accessed via the SFX button).
You should also search the Medline PubMed database, because they are crucial for the field of medicine. Medline PubMed also features the Full Text Finder linking service.