This problem is solved in:

V. Dujmović, D. Eppstein, R. Hickingbotham, P. Morin, D. R. Wood. Stack-number is not bounded by queue-number. Combinatorica, accepted in 2021 https://arxiv.org/abs/2011.04195

## This problem is solved

This problem is solved in:

V. Dujmović, D. Eppstein, R. Hickingbotham, P. Morin, D. R. Wood. Stack-number is not bounded by queue-number. Combinatorica, accepted in 2021 https://arxiv.org/abs/2011.04195