Aha ...hiding glass from us !
Any chance of a look at the 2nd piece then ?
The first may or may not be Zeman. I do know that he does NOT sign his glass. I think he does use lables but would have to check on that.
Other possibilities are : Igor Muller & Tomas Oliva
Igor studied under Stanislav Simunek at Art Glass Institute in Zelezny Brod and was influenced by Tomas Oliva, also at Zelezy Brod.
From 1994 to 1997 Igor worked at the Simon Pierce Glassworks, Vermont. He founded a small art glass studio in the Czech Republic in 1997.
I don't know so much about Tomas Oilva but both work in the heritage style I believe. Igor collaborates with the Art-Industrial Museum in Prague on replicas of antique art glass.