Jens Fisseler: Toward Markov Logic with Conditional Probabilities. FLAIRS Conference 2008: 643-648 http://www.aaai.org/Papers/FLAIRS/2008/FLAIRS08-144.pdf
There is a continuation of that project with a paper from 2011 (co-authered again by Jens Fisseler): Matthias Thimm, Gabriele Kern-Isberner, Jens Fisseler: Relational Probabilistic Conditional Reasoning at Maximum Entropy. ECSQARU 2011: 447-458 http://www.mthimm.de/pub/2011/Thimm_2011.pdf