The phrase "also a great source" is correct and usable in written English.
You can use it when referring to something that provides valuable information or resources in addition to other sources mentioned.
Example: "In addition to the textbook, the online database is also a great source for research materials."
Alternatives: "additionally a valuable resource" or "also an excellent reference".
They are also a great source of fibre and glucose, the main energy source for the brain.
"We searched through a lot of magazines, also a great source, and we did some research on the Internet," he added.
These are also a great source of information and advice for the whole family, as well as support to help young carers make the best choices for themselves.
Peanuts are also a great source of B vitamins, which are especially good for your hair, skin and muscle tone, and they contain the same amounts of antioxidants as strawberries.
Not only does milk contain about a third of the sugar of juice, it's also a great source of the protein, calcium, vitamin D and magnesium that growing kids need.
Of course, a mackerel is more than just its oil: according to the British Dietetic Association, oily fish are also a great source of lean protein and minerals such as iron, zinc, selenium and iodine, plus vitamins A and D – the last being particularly useful at this time of year, when most of us aren't seeing much sunlight.
Smarter state capitalism was also a greater source of international competitive advantage than the state intervention often seen in the past.
Twitter can be great fun and it can also be a great source of information.
The white pine needles are also is a great source of vitamin C, in tea.
I also have a great source for people who are ready to use blogging as a learning tool.
However, a turbulent environment where external changes are non-linear and discontinuous can also be a great source of opportunity for firms to strengthen their existing capabilities and/or develop new ones which enable firms to overcome their organizational inertia and myopia of learning (Levinthal and March 1993; D'Aveni 1994; Ambrosini and Bowman 2009; Schilke 2014).
