Krel' A.A., Furtseva L.N. (1968) Methods of determining hydroxyproline in biological fluids and their use in clinical practice. Voprosy Meditsinskoi Khimii, 14(6), 635-640.

Krel' A.A. et al. Methods of determining hydroxyproline in biological fluids and their use in clinical practice // Voprosy Meditsinskoi Khimii. - 1968. - V. 14. -N 6. - P. 635-640.

Krel' A.A. et al., "Methods of determining hydroxyproline in biological fluids and their use in clinical practice." Voprosy Meditsinskoi Khimii 14.6 (1968): 635-640.

Krel', A. A., Furtseva, L. N. (1968). Methods of determining hydroxyproline in biological fluids and their use in clinical practice. Voprosy Meditsinskoi Khimii, 14(6), 635-640.