You can find a lot of conference and journal papers on speech enhancement but finding the right speech enhancement books which cover necessary and practical aspects of the subject is a challenge. I have found few good books which I am listing below and I hope that you will also enjoy reading them.
Speech and Audio Processing in Adverse Environments (Signals and Communication Technology) Eberhard Hänsler and Gerhard Schmidt
Advanced Signal Processing and Noise Reduction, 2nd Edition Saeed V. Vaseghi
Noise Reduction in Speech Processing (Springer Topics in Signal Processing) Jacob Benesty, Jingdong Chen, Yiteng Huang, and Israel Cohen