Many companies are known by a popular name or a tradename which is different from their official name. Most resources will list companies only by their official name. Be aware of companies which are named after an individual. Furthermore, a resource may either include or ignore first names and initials when entering and alphabetizing, and some resources are inconsistent. Also, initials can be alphabetized in different manners.
Many researches go awry because of misspellings.
Be prepared with spelling variations, even when you feel you are certain of the spelling. A publicly-held company is one that openly sells stock to the public. Those who purchase the stock have an ownership interest in the company. Because of Securities and Exchange Commission regulations, a wealth of information is available for public companies. This same detail of information does not exist for private companies.