| Srivastava et al., Chemical Abstracts, vol. 68 (1968) 12627b. |
| Murayama et al, Chemical Abstracts, vol. 85(1976) 144593y. |
| Morita et al, Chemical Abstracts, vol. 89 (1978) 146990g. |
| Endo et al, Chemical Abstracts, vol. 89 (1978) 44990q. |
| Tsivunin et al, Chemical Abstracts, vol. 74 (1971) 53927s. |
| Pudovik et al, Chemical Abstracts, vol. 72 (1970) 12830v. |
| Noetzel et al, Chemical Abstracts, vol. 85 (1976) 47586r. |
| Zabusova et al, Chemical Abstracts, vol. 66 (1967) 10998h. |
| Pudovik et al, Chemical Abstracts, vol. 80 (1974) 83134x. |
| Khairullin et al, Chemical Abstracts, vol. 69 (1968) 59335r. |
| Pudovik et al, Chemical Abstracts, vol. 70 (1969) 115241s. |
| Pudovik et al, Chemical Abstracts, vol. 71 (1969) 3478p. |
| Lomakina et al, Chemical Abstracts, vol. 63 (1965) 15477c. |
| Kijima et al, Chemical Abstracts, vol. 88 (1978) 136815u. |
| Mel'nikov et al, Chemical Abstracts, vol. 57 (1961) 117072c. |
| Garibina et al., Chemical Abstracts, vol. 105 (1986) 133978. |