List of Publications:

2. On Structural Descriptions of Lower Ideals of Trees. (with N. Robertson), Journal of Graph Theory, Vol. 50(2005), 220-233.

3. Density of universal classes in $K_4$-minor-free graphs. (with J. Nesetril J. of Graph Theory 54(1):13-23 (2007))

4. Minimal universal and dense minor closed classes. (with J. Nesetril, Eur. J. Combin. 27(7):1159-1171 (2006))

5. On a new reformulation of Hadwiger's Conjecture. (with Reza Naseraser) Discrete Math., 306 (2006), 3136-3139.

2. On well-quasi-ordering lower sets of finite trees, a new proof (Submitted to Journal of Combin. Thy. Ser. b)

3. Finite dualites and map-critical graphs on a fixed surface (With J. Nesetril, Submitted to Journal of Combin. Thy. Ser. b)

4. Homomorphisms of triangle-free graphs without K_5-minor. (with Reza Naserasr and Riste Skrekovski, Submitted to Discrete math.)

5. Two short proofs to two theorems of Chien, Hell and Zhu. (With Tracy Holt, Submitted to JGT)

6. On the chromatic-number of alphabet-overlap graphs. (With Debra Kinsley and Attila Por, Submitted to JCMCC)

2. A minimal apex 5-chromatic K4-free graph (with J. Sebastian and Riste Skrekovski, in preparation)

3. On well-quasi-ordering trinfinite trees, a new proof. (in ppreparation)