"Recent work on naturally occurring nitrogen heterocyclic compounds"@en . "Recent work on naturally occurring nitrogen heterocyclic compounds" . . . . . . . . . . "Recent work on naturally occurring nitrogen heterocyclic compounds report of a symposium held ... at the University College of the South West of England, Exeter, 13-15th July, 1955"@en . . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a Symposium held by the Chemical Society at the University College of the South West England, Exeter, 13th - 15th july, 1955" . . . . . . . . "Conference papers and proceedings" . "Conference papers and proceedings"@en . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South West of England, Exeter, 13-15 July 1955"@en . . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South-West of England, Exeter, 13th-15th July, 1955" . "Recent Work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South West of England, Exeter, 13.-15. July, 1955" . . . . . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South West of England, Exeter, 13th-15th July, 1955"@en . . . . . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held ... at the University College of the South West of England, Exeter, 13th-15th July, 1955"@en . . . . "Recent work on naturally occurring nitrogen heterocyclic compounds; report of a symposium held ... at the University College of the South West of England, Exeter, 13-15th July, 1955" . . . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South West of England, Exeter., 13th-15th July, 1955" . . . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South-West of England, Exeter,13th-15th July,1955"@en . "Recent work on naturally occurring nitrogen heterocyclic compounds : report of a symposium held by the Chemical Society at the University College of the South West of England, Exeter. 13-15 July, 1955" . . . . . "Symposium held by the Chemical Society at the University College of the South West of England (1955.07.13-15 Exeter)" . . . "Composés hétérocycliques Congrès." . . "Royal Society of Chemistry. Symposium" . . "Composés de l'azote." . . "Heterocyclic Compounds Congresses." . . "Azote Congrès." . . "Nitrogen Congresses." . .