Yes, Anna Marina. Any quotes from Strong's in WTS publications are okay, because they have been pre-approved by the WTS writing staff. But general private reading of Strong's is discouraged and the WTS Concordance is best.)
As to Greek and Hebrew words, in the past the WTS did use the original words in their publications when discussing their meaning for jws today, such as agape, psyche, etc. Except for the NWT Study Notes, now in 90% the WTS publications, the WTS says "Greek word" and then the definition but not the word itself.
I think in today's jw world, most jws have no idea about the four Greek words for love (English having only one word).
-----This is the most recent reference I found in 2017, then nothing until 2009 (note the 4th is eros, not found in the Bible)
https://wol.jw.org/en/wol/d/r1/lp-e/2016603?q=agape+philia+storge&p=par
The Bible emphasizes the importance of love. Tender affection (Greek, phi·liʹa) is needed in a marriage. Romantic love (eʹros) brings delight, and love for family (stor·geʹ) is vital when children enter the picture. However, it is love based on principle (a·gaʹpe) that ensures the success of a marriage.
(Plus, I have not found the reference, but not too long ago, jws were discouraged from doing research outside the WT study articles to share at the WT study, even in other WT publications, that all the research that was needed in the article had been provided by the WTS/GB.) If someone else on JWN has that reference, can you share it here?)