The Dutch National Bibliography up to 1801
(Colophon: Amsteldam, J. Helders and A. Mars booksellers), [last quarter 18th century]
3 Exemplare. — STCN ID: 235160687
De verschyning van Apollo in zyn' tempel
(Colophon: Amsteldam, J. Helders and A. Mars), [4th quarter 18th century]
2 Exemplare. — STCN ID: 297487450
Amsteldam, printed by J. Helders, [between 1772 and 1783]
2 Exemplare. — STCN ID: 291935354
(Colophon: Amsteldam, J. Helders and A. Mars booksellers), [last quarter 18th century]
3 Exemplare. — STCN ID: 30789441X
Amsterdam, J. Helders, [not before 1772]
9 Exemplare. — STCN ID: 172227518
Agon, sulthan van Bantam. Treurspel. / By Onno Zwier van Haren
Amsteldam, sold by J. Helders, [ca. 1775?]
3 Exemplare. — STCN ID: 170560724
Amsterdam, J. Helders printer, 1779
5 Exemplare. — STCN ID: 162250053
Amsteldam, J. Helders, 1779
3 Exemplare. — STCN ID: 164012745
Amsterdam, J. Helders printer, 1779
3 Exemplare. — STCN ID: 297584669
Het eiland van verwarring; blyspel. / By H. van Elvervelt
Amsteldam, J. Helders printer, 1780
5 Exemplare. — STCN ID: 142925438