[SteveR]

Following on from my other thread on this board in which I wrote (in part):

Back in high school and college I took German classes for 5 years and had become fairly fluent. Those classes ended in 1983 however...

Early this year I decided it was time to re-learn to read German (fortunately I still have all of my textbooks and dictionaries from long ago). The re-learning process (aided by a translation app on my phone) went easier than expected.

No disrespect whatsoever to the authors (I ask because these were first published quite some time ago), can someone remark on how the following books have stood the test of time?

The JG27 unit history by Girbig and Ring

and

the JG 51 unit history by Gebhard Aders.

Are they still considered to be accurate or should I look for more recent works on these units? What level of detail is presented in these two?

Thanks in advance for any advice or insight on these!