The last chance for desperate refugees in the Czechoslovak interior was the international city of Shanghai, surrounded by Chinese territory occupied by the murderous Japanese army. There, only one thing was required: a landing fee in cash, and in dollars. The journey from Prague to Shanghai itself was also very financially demanding.
Dr. Weinstein decided to go ahead alone, with the understanding that as soon as he earned the dollars needed to purchase the immigration certificates for his wife and children, he would send buy these and get them to the family.
He did indeed buy the certificates and they have survived to this day, but they were never used. After the termination of alliance between Nazi Germany and Soviet Union, they no longer could reach their recipients. The post office delivered them only in 1946.
Shanghai landing certificates for Hanuš and Anna. Family archive / Collections of the Jewish Museum in Prague