I would have to agree with the posters above. There can, and will be, different tiered searches under Google to reach the exact topic you are looking for. Outside of that, you need to examine the exact identifier of your "business." Some medical transporters are not EMTs. Some transporters are simply used to take patients to doctor's appointments (when they cannot drive themselves). You need to be very direct when describing the business and choosing where to advertise based upon the most correct definition of the business.
Depending on whether or not all of the drivers/attendants are going to be EMTs just like in ambulances, you could classify it under ambulances in the Yellow Pages. Transportation or Medical Tranports might be the better general category, but when advertising, I would want the business to be listed right next to the other ambulance companies I am trying to capture market share from.
I agree with #5. From the information you have given us, you are going to have to tighten your assignment considerably to target a particular context, so as you are doing your research you might want to begin to consider how you might narrow your project down into something more manageable.
Once you have found your Non-Emergency Medical Transportation listing on Google, you can then start searching sources listed for the specifics you need to research, such as market size, companies offering such services, and so on. My suspicion is that you are going to need to determine a particular locale and base your information upon the situation in that area. Urban areas may have a great deal to offer in this type of market; small towns and rural areas may have very little if any business-based transportation of this type.
The overreaching industry that non-emergency medical transportation falls under is Transportation. The sub-industry is Medical Transportation. The tertiary level industry is Non-Emergency Medical Transportation.
These websites might help you with your project:
I searched Google looking for "non-emergency medical transporation" and found many relevant sites by employing that term. It could be, then, that the term you asked about is the relevant term for this industry. Here, for instance, is a government report about this industry:
I preparing a business plan. Conducting a Industry Research. I was told to do a Via Google Search. I have to use the following queries to find the market size,trends and the names of key competitors in that industry. That's why I asked what is the industry I should use when conducting a Industry Research.
[ Industry Name] "market size"
[Industry Name ] "statistics
[Industry Name ] "market trends"
[Industry Name] companies
[Industry Name] "market share"