Part I. Modular Forms and their Variants:
3. Modular forms for SL(2,Z)
4. Variants of modular forms
5. Quantum fields on a torus
6. Congruence subgroups and modular curves
7. Modular forms for congruence subgroups
8. Modular derivatives and vector-valued modular forms
9. Modular graph functions and forms
Part II. Extensions and Applications:
11. Singular moduli and complex multiplication
13. Toroidal compactification
14. S-duality of type IIB superstrings
15. Dualities in N = 2 super Yang-Mills theories