A Y KatukizaM RonteltapC B NiwagabaJ W A FoppenF KansiimeP N L Lens
Poor sanitation in urban slums results in increased prevalence of diseases and pollution of the environment. Excreta, grey water and solid wastes are the major contributors to the pollution load into the slum environment and pose a risk to public health. The high rates of urbanization and population growth, poor accessibility and lack of legal status in urban slums make it difficult to improve ...
Xu and Wu proved that if every $5$-cycle of a planar graph $G$ is not simultaneously adjacent to $3$-cycles $4$-cycles, then $4$-choosable. In this paper, we improve result as follows. If without pairwise $3$-, $4$-, $5$-, $6$-cycle,
