Transactions of the AMS. Year 1928. Volume 030. Number 04.


Some non-linear problems in approximation
Dunham Jackson
621-629


Second-order differential systems with integral and $k$-point boundary conditions
William M. Whyburn
630-640


Analytic functions of hypercomplex variables
P. W. Ketchum
641-667


Concerning limiting sets in abstract spaces
R. G. Lubben
668-685


Riesz summability for double series
Florence M. Mears
686-709


The inverse problem of the calculus of variations in higher space
David R. Davis
710-736


Types of motion of the gyroscope
A. H. Copeland
737-764


The invariant integral and the inverse problem in the calculus of variations
Thomas H. Rawles
765-784


The projective differential geometry of systems of linear homogeneous differential equations of the first order
Ernest P. Lane
785-796


The behavior of a boundary value problem as the interval becomes infinite
W. E. Milne
797-802


The second derivative of a polygenic function
Edward Kasner
803-818


Diophantine equations in division algebras
Ralph G. Archibald
819-837


On the degree of approximation to an analytic function by means of rational functions
J. L. Walsh
838-847


Existence and oscillation theorems for non-linear differential systems of the second order
William M. Whyburn
848-854


Errata: ``A symbolic theory of formal modular covariants'' [Trans. Amer. Math. Soc. {\bf 24} (1922), no. 4, 286--311; 1501227]
Olive C. Hazlett
855


Errata: ``On the irregular cases of the linear ordinary difference equation'' [Trans. Amer. Math. Soc. {\bf 30} (1928), no. 3, 507--541; 1501443]
C. Raymond Adams
855