1. Stress and Strain Analysis

2. Elasticity and Elastic Boundary-Value Problems

3. Fundamentals of Plasticity Theory

For those willing to go through some challenging reading, Lubliner's text on Plasticity Theory has much to offer. It is dense, given the author's declared appreciation for conciseness, but it is reach with information and rigorous in treatment. Make sure to make use of the errata.

The recent text by Hai-Sui Yu, which targets soil plasticity, is a good overview of various aspects of plasticity theory.

4. Basic Soil Constitutive Models

5. Theoretical Geomechanics and Relation to Practice

6. Numerical Methods

7. Programming with FORTRAN