21
by Helvétius
Published 1758
Chez Durand

22
by Helvétius
Published 1759
[Printed for the translator, and sold by Mr. Dodsley and Co. [and 8 others]

23
by Helvétius
Published 1777
[s.n.]

24
by Helvétius
Published 1768
Chez Durand

25
by Helvétius
Published 1769
Chez Durand

26
by Helvétius
Published 1772
[s.n.]