I. Introduction  
A. Previous Work  
B. Semi-supervised Learning  

II. Semi-supervised Deep Learning  
A. Pre-training for Semi-supervised Deep Learning  
B. Pseudo-label Semi-supervised Deep Learning  
C. Regularized Semi-supervised Learning  

III. Dealing with Distribution Mismatch in SSDL  
A. OOD Data Detection  
B. Semi-supervised Deep Learning Methods Robust to Distribution Mismatch  

IV. Open Challenges