TY - RPRT TI - Transition between positive and negative hexagons in optical pattern formation. AU - T Ackemann AU - YA Logvin AU - A Heuer AU - W Lange PY - 1995 DO - 10.1103/physrevlett.75.3450 UR - https://pubmed.ncbi.nlm.nih.gov/10059589/ ID - 10059589 ER -