There is a short write up on www.geomancy.net regarding tombs. You can browse throught the topic : The Landscape
Under this topic, it is recommended that you read topics like :
1. Four Symbolic Animals,
2. Burial tombs,
3. Ming tombs and
4. Qing tombs
So far, the only few books that have some references to tombs are by Eveyln Lip. Her book " Geomancy " has a few pages on this but overall, it mentions that previously graves are on a North -- South alignment.
Under my website: Case Studies please use the find feature, to search for Evelyn, there is a short information on this.
Center for Feng Shui Research