Sporadic Ca and Ca+ layers at mid-latitudes: Simultaneous observations and implications for their formation

Sporadic E movement followed with a pencil beam high frequency radar

Sporadic source of ionization in the D- and E-regions of the nocturnal ionosphere at middle latitudes

Sporadic-E as a tracer for atmospheric waves

Sporadic-E associated with the Leonid meteor shower event of November 1998 over low and equatorial latitudes

Sporadic-E layers and unstable wind shears

Spread F and the structure of equatorial ionization depletions in the southern anomaly region

Spread F plasma bubble vertical rise velocities determined from spaced ionosonde observations

Spread-Es structure producing apparent small scale structure in the F-region

Spread-F and radio wave scintillations near the F-region anomaly crest

Spread-F during quiet and disturbed periods at midlatitudes

Spread-F occurrence in mid- and low-latitude regions related to various levels of geomagnetic activity

Spread-F-like irregularities observed by the Jicamarca radar during the day-time

Springtime effects in the mesosphere and ionosphere observed at northern midlatitudes

SSM/T forward modelling using neural networks.

Stability borders and classification of density perturbation propagations in deDonder-gauge on a cosmological background

Stability of a shell around a black hole

Stability of gas clouds near quasi-stellar objects

Stability of open universes

Stability of the auroral plasma - Parallel and perpendicular propagation of electrostatic waves