Ring oscillator not oscillating
Page 31 in this document shows a similar circuit. 



Apart from the slightly different architecture three interesting aspects: 


C4 creates a start condition by introducing an imbalance in the ring;
BJT's instead of MOSFET's (MOSFET's in the circuit from the blog you refer to);
Much lower values for the resistors, BJT's are current driven rather than voltage driven like MOSFET's are. 


In my experience the circuit refuses to run on 6V, but 9-12V worked fine.