Using FamilySearch to your advantage can take you a long way in finding something as simple as an out of print book. Many of the books available are actually on microfilm which means that it is simply a request away. You don't have to spend hundreds of dollars on a book that you can gain access to very easily. If you find you like to have the book in your personal library then that is different.
Recall in my prior post that prior to ordering films, check to see if the film hasn't already been ordered; make sure you do this to save funds on other films that may not be available. This will also save you time. The fee you pay is to cover the cost of duplicating the film and also to keep the system running in making them available to all as well as covering shipping costs to a location near you. The rentals are only good for a few weeks so you can easily request an extension and if you need it beyond that, the third time you request the extension keeps the film at your FHL permanently for all to view including yourself.
So today I had a cousin that matches me via DNA mention that they needed access to Estela Cifre de Loubriel books, like many starting off, most have no idea that these out of print books are available. So below is a link that provides you access to all the Cifre de Loubriel books they currently have in their catalog which covers many different migrants to the island of Puerto Rico.
Link to Family Search: Estela Cifre de Loubriel books
Another known author of genealogy and history is Fernando Pico
Link to Family Search: Fernando Pico books
There are more books and the best way of using the catalog search is by using keywords or keyword phrases. I previously spoke about how to find information on churches and other records. The same goes with finding information you seek including books.
Most search engines use keywords or keyword phrases. So imagine you're looking to fix a cracked screen on your phone. You wouldn't type into Google "Phone screen", you'd type "How to fix cracked phone screen". The recommendation I give anyone is to try one to two words and if you get too many hits then keep reducing the list by adding another word. If your search comes up empty then change that word to something similar until hopefully you find what you seek.
So below is the search screen window for the catalog.
The same goes if you try "Puerto Rico", you'll wind up getting too many hits but if you try "Mayaguez Puerto Rico", you'll get a more manageable list. You can go further down if you want to drill down by typing "History Mayaguez Puerto Rico". This same concept can be applied to Domincan Republic or any other place you seek to find information on.
How was I able to find all of the census records? Very easily, keywords and keyword phrases. Arming yourself with this knowledge take away a lot of the struggle in finding information. I recommend that you keep a notebook and write down what it is you seek, simple one liners. Then search for this in both languages on FamilySearch.
I highly recommend using a translator because a word that easily comes to mind for most of us for Census is Censo. However the words Padron and empadronamiento also mean census. You also have to think of different reason for a census such as riqueza or ayuntamiento; one meaning the wealth of the population and the other meaning town hall. These are also many reasons for taking a "census" of a town or village. That is how I found the Hato Grande aka San Lorenzo census I shared on another post. I also took looked through the images to see what type of information was attached to the record. When I found that census, it had been there for years but no one ever spoke of ever finding it.
This is where you'll see other items available such as history books, protocoles notariales (protocol notaries) which include wills, as well as many other records. Now if the only format they have of an item is in book format then the only way you can view this item is by visiting the main FHL in Utah. If this isn't feasible for you then they provide you the link to search on the WorldCat Book website which is basically a global catalogs of libraries. Check with your regular local library to see if you can use this feature. I have successfully been able to borrow 2 books in search of records on my family tree. This same exact concept can be applied to even those who are researching their Dominican ancestry or anywhere else. Good luck in your research!