[1] M. Bartušek, Z. Došlá:
On the limit-point/limit-circle problem for nonlinear third order differential equations. Math. Nachr. 187 (1997), 5–18.
MR 1471135
[2] M. Bartušek Z. Došlá, and J. R. Graef:
On $L^2$ and limit-point type solutions of fourth order differential equations. Appl. Anal. 60 (1996), 175–187.
MR 1623388
[3] M. Bartušek Z. Došlá, and J. R. Graef:
Limit-point type results for nonlinear fourth order differential equations. Nonlinear Anal. 28 (1997), 779–792.
MR 1422183
[4] M. Bartušek Z. Došlá, and J. R. Graef:
Nonlinear limit-point type solutions of $n$th order differential equations. J. Math. Anal. Appl. 209 (1997), 122–139.
MR 1444516
[5] N. Dunford, J. T. Schwartz:
Linear Operators; Part II: Spectral Theory. Wiley, New York, (1963).
MR 1009163 |
Zbl 0128.34803
[6] M. S. P. Eastham:
The limit-$2n$ case of symmetric differential operators of order $2n$. Proc. London Math. Soc. (3) 38 (1979), 272–294.
MR 0531163 |
Zbl 0398.34021
[7] M. S. P. Eastham, C. G. M. Grudniewicz:
Asymptotic theory and deficiency indices for fourth and higher order self-adjoint equations: a simplified approach. in: Ordinary and Partial Differential Equations (W. N. Everitt and B. D. Sleeman, eds.), Lecture Notes in Math. Vol 846 Springer Verlag, New York, 1981, pp. 88–99.
MR 0610637 |
Zbl 0514.34047
[8] W. N. Everitt:
On the limit-point classification of fourth-order differential equations. J. London Math. Soc. 44 (1969), 273–281.
MR 0235187 |
Zbl 0162.39201
[9] M. V. Fedorjuk:
Asymptotic method in the theory of one-dimensional singular differential operators. Trudy Mosk. Matem. Obsch. 15 (1966), 296–345.
MR 0208060
[10] J. R. Graef:
Limit circle criteria and related properties for nonlinear equations. J. Differential Equations 35 (1980), 319–338.
MR 0563385 |
Zbl 0441.34024
[11] J. R. Graef:
Limit circle type results for sublinear equations. Pacific J. Math. 104 (1983), 85–94.
MR 0683730 |
Zbl 0535.34024
[12] J. R. Graef:
Some asymptotic properties of solutions of $(a(t)x^{\prime })^{\prime } - q(t)f(x) = r(t)$. in: Differential Equations: Qualitative Theory (Szeged, 1984), Colloquia Mathematica Societatis János Bolyai, Vol. 47, North-Holland, Amsterdam, 1987, pp. 347–359.
MR 0890550
[13] J. R. Graef, P. W. Spikes:
On the nonlinear limit-point/limit-circle problem. Nonlinear Anal. 7 (1983), 851–871.
MR 0709039 |
Zbl 0535.34023
[14] R. M. Kauffman T. T. Read, and A. Zettl:
The Deficiency Index Problem for Powers of Ordinary Differential Expressions. Lecture Notes in Math. Vol. 621, Springer-Verlag, New York, 1977.
MR 0481243
[15] R. M. Kauffman:
On the limit-$n$ classification of ordinary differential operators with positive coefficients. Proc. London Math. Soc. 35 (1977), 496–526.
MR 0460780 |
Zbl 0382.47025
[16] M. A. Naimark:
Linear Differential Operators, Part II. George Harrap & Co., London, 1968.
Zbl 0227.34020
[17] R. B. Paris, A. D. Wood:
On the $L^2$ nature of solutions of $n$-th order symmetric differential equations and McLeod’s conjecture. Proc. Roy. Soc. Edinburgh 90A (1981), 209–236.
MR 0647603 |
Zbl 0483.34014
[18] B. Schultze:
On singular differential operators with positive coefficients. Proc. Roy. Soc. Edinburgh 10A (1992), 361–365.
MR 1159190 |
Zbl 0767.34058
[19] P. W. Spikes:
On the integrability of solutions of perturbed nonlinear differential equations. Proc. Roy. Soc. Edinburgh Sect. A 77 (1977), 309–318.
MR 0514125
[20] P. W. Spikes:
Criteria of limit circle type for nonlinear differential equations. SIAM J. Math. Anal. 10 (1979), 456–462.
MR 0529063 |
Zbl 0413.34033
[21] H. Weyl:
Über gewöhnliche Differentialgleichungen mit Singularitäten und die zugehörige Entwicklungen willkürlicher Funktionen. Math. Ann. 68 (1910), 220–269.
MR 1511560