Cannell SA.
Midwives Chron. 1975 Dec;88(1055):405.
PMID: 1042528

[No authors listed]
Nurs Mirror Midwives J. 1972 Dec 01;135(22):16-8 concl.
PMID: 4486313

Rankin S.
Nurs Mirror. 1980 Dec 11;151(24):22-3.
PMID: 6905136

Newson K, Hallworth C.
Nurs Mirror. 1980 Jul 10;151(2):iii-vi, x.
PMID: 6901138

Shindo Y, Miura I, Iwagawa Y, Takagi N.
Kango Kyoiku. 1976 May;17(5):298-305.
PMID: 1046470

Nakajima C, Oshima H.
Josanpu Zasshi. 1975 Aug;29(8):396-400.
PMID: 1042219

Kitson LM.
Midwives Chron. 1980 Feb;93(1105):37-40.
PMID: 6898277