To what extent are the following books sound and reliable: "Sahih Fiqh Al-Sunnah" by Abu Malik, "Mawsu'at Al-Fiqh Al-Islami" by Abd Al-Halim Owais, and "Al-Fiqh Al-Islami wa Adillatuh" by Wahbah Al-Zuhayli? And is there a verified edition of Al-Shawkani's "Nayl Al-Awtar"?

We have no knowledge of the book "Sahih Fiqh As-Sunnah" by Abu Malik, nor "Mawsu'at Al-Fiqh Al-Islami" by Abd Al-Halim Uwais. As for the book "Al-Fiqh Al-Islami wa Adillatuh" by Wahbah Al-Zuhayli, it is a good book that summarizes the essence of the four madhhabs, and it relied on authoritative classical texts. And the book "Nayl Al-Awtar" by Al-Shawkani, was verified by Muhammad Subhi Hasan Hallaq in eight volumes.